Powermaster Prime's animation model as used in the commercials and as a character guide for the Marvel comics is a composite of the second and third designs. The body of the model is actually a straight tracing of the concept lineart for the third version (including its different rifles and twin faux shoulder stacks), with a slightly simplified drawing of the second version's head drawn on top.
Prime's trailer unfolds via a spring-loaded transformation mechanism in a battle station that is positively bristling with varied weaponry. In addition to the disc launcher, it is armed with a "ripple-fire" missile launcher that fires five missiles, an air-powered rocket launcher like the one previously seen on Hero Optimus Prime, and a small laser cannon that mounts on the base's main tower. Both the missile launcher and laser cannon can disconnect and be held by Prime; his LED-fist will illuminate the laser cannon like it does his sword. Additional missiles and a second rocket are stored in grooves inside the sides of the trailer.
If Optimus allowed the cured Autobots to charge headlong into battle, he and the rest of the Autobots who were still running low on fuel stayed behind as back-up to the main charge. The Autobots’ first wave of warriors were quickly overpowered by the arrival of Megatron, prompting Optimus to lead the energy-depleated Autobots into the fray. Optimus’s opening volley struck down Shockwave. Optimus and his troops soon found themselves running on empty, and Optimus called for a retreat. Thankfully, the Decepticons were damaged enough through the course of the battle, causing them to retreat as well.
The Decepticons' initial strike came abruptly and brutally, devastating entire districts of Metropolis. Optimus was meeting with Hot Rodimus as this took place, and was nearly overcome with grief when Ratchet informed him of the carnage the Decepticons had wrought. Steeling himself, Optimus coordinated the city's defenses, ordering his troops to be dispatched where they were most needed to repel the invasion. Upon spotting an old enemy on one of the nearby monitors, Optimus geared up to go in the field himself. Arming himself with his favorite pistol, Optimus resolved to take down Megatron. Raid
The third version  would quite possibly have been the most gimmick loaded Transformer in the history of the line, simultaneously being a Powermaster, Headmaster, and Triple Changer. The Headmaster also would have been a Triple Changer, turning into a sort of armored four-wheeled rover (Roller II?) and robot as well as a rather silly looking Optimus Prime head with four vertically aligned wheels jutting off the sides. It seems that when the extra Headmaster gimmick was scrapped, the super mode head remained separate rather than being reintegrated into the trailer hitch such as on the earliest design. Notably, the body of this design is extremely close to the final design.
Bumblebee may be beloved, but so is Optimus Prime and writers have seemingly killed off Optimus a million times in different continuities. So it can’t be too much of a surprise to know that Bee has met his maker on a few occasions as well. In the “Dark Cybertron” storyline of the IDW Generation 1 continuity, Decepticon Shockwave goes mad with power and wants to destroy all Autobots and Decepticons. In the process, Shockwave kills Bumblebee and sets off a chain of events that leads to retribution against Shockwave.
In the Escalation miniseries, Megatron engages Prime and, boosted by Ore-13, overcomes him. Believing their leader dead, the rest of the Autobots attempt to buy the newly arrived Hot Rod time to collect the clone. Prime, who had transferred his consciousness to a backup memory in his trailer command post, advised them to exploit Ore-13's weakness and assault Megatron all-out, catalyzing the Decepticon leader's Energon supply and crippling him.
This miniature model kit of Energon Optimus Prime comes unassembled and unpainted, moulded mainly from white, red and black plastic and featuring some stickers for essential detail. Standing at around 4.5 inches tall, he comes with his Prime Force drones and can combine with them in the usual ways; while Fire-1, Gyro-2 and Digger-3 are moulded in their normal colours, Submarine-4 is stuck being black, and like every other non-color-molded, non-stickered detail on the kit, must be painted by the buyer. Prime's transformation involves removing his feet and head (an alternate Super Mode head is included, as his antenna does not transform into a helmet), and he does not come with a trailer for the Prime Force, but his gun can shoot small orange plastic BBs via a pressure-launching mechanism, and he comes with a small gold-chromed Energon star that fits onto his left shoulder. The kit also comes with "Episode 1" of the "Optimus Prime VS Scourge" mini-comic, printed on the back of the instructions.
3. Licensed themes: In the 80’s the Lego sets were more generic and interchangeable among themes. There were the basic Space, Town, Castle themes. The color schemes within a theme were more homogeneous (i.e. Blacktron sets or Mtron sets all had a common color scheme). Since there was no “fictional” real life object being copied, piece selection tended to emphasize versatility over “realism”. Almost every Lego set of the past had pictures of alternate models featured on the boxes and instructions that was meant to inspire a child to not just build the model featured in the instructions, but to embark on the mental challenge of making their own creations.
Oh, also, I should add that I would like to see if this trend is the same for specific themes, or just over all themes. Although I would guess that the individual themes would show the same general trend you discuss here, one reason individuals might believe in the “price increase fallacy” might be because of the individual themes they support. But again, I think that if you do this, you will find the themes fit the trend as well. If you are looking to go into the numbers more, this might be an interesting area to investigate.
In "Decepticon Air", Optimus receives a secret distress call from the Elite Guard ship that is carrying Decepticon prisoners. During the flight, the ship enters an electrical storm, which revives an inactive Swindle and he frees other prisoners to take over the ship. Transwarping to the ship via Swindle's personal transport field, Optimus joins forces with the Elite Guard, rounding up most of the Decepticons in the end.
The Autobots helped repair a Smitco Oil Refinery site which the Lazarus-controlled Transformers had attacked. Optimus had no answer for Spikes accusation that the Transformers' presence on Earth was responsible for the destruction. When Megatron's activities at Lazarus's base were spotted by the military, Optimus insisted on the Autobots going in without backup. They discovered Megatron in the middle of a plan to reformat Earth into a new Cybertron using a cyber-virus. Optimus rejected Megatron's suggestion he should just let it happen, but while the two factions fought, the human military unleashed Operation Clean-Up, dropping a bomb on them. Prime Directive #3
A redeco of of the Cyber Commander toy above, this Prime features grey plastic replacing the original blue, some deco differences on the arms, body & legs. He also features a flame tampograph on the sides of his vehicle front. He comes in an altered packaging that replaces the first version's painted prototype stock photos with CG renders depicting the new deco, and also features a new Hasbro product code number, thus making him officially a separate product rather than a drastic running change variant.
Thanks to TFW2005 user Fc203, we have some screencaps from what appears to be a stop-motion review video featuring Studio Series Shatter, among other Transformers and non-Transformers toys. The screencaps give us a good look at her robot and alt mode as well as a few poses. Like her partner Dropkick, Shatter only comes with one alt mode. However, that alt mode is her car mode and not her aircraft mode; whereas Dropkick is the opposite. She also seems to be sporting a bit more of a generic head that isn’t quite movie-accurate, but the rest of the figure seems to pay a good deal of homage to her pre-jet mode on-screen model.
According to the bio printed in the Transformers Collectors Club magazine, Optimus Prime was a member of the Cybertron Dimensional Patrol, but was abducted by Unicron. It is unknown whether he repainted himself yellow before being abducted or if the recoloration was due to the radiation emanating from Unicron, which has a tendency to recolor Cybertronians.
Optimus confronted his archenemy on the battlefield, though he had to knock Starscream aside to get to him first. Due to a nearby explosion that rocked the battlefield, Optimus nearly lost both his stance and his head when Megatron took advantage of the opening. But Optimus's quick reflexes allowed him to shift to vehicle mode and back, dodging Megatron's attack and striking back in the process. As the battle raged on, both combatants found themselves evenly matched. Then Ratchet contacted Optimus with dire news; the Decepticons had managed to abduct SARA! Fate
"During the Cybertronian Civil War, Sentinel Prime was killed. Prior to his destruction, he bestowed the Matrix of Leadership to Optimus Prime, who became the new leader of the Autobots. Despite being one of the youngest Cybertronian leaders, Optimus demonstrated extraordinary courage and wisdom in the war against the Decepticons. He: treated all lives with benevolence, fought for freedom and peace, and continues to fight to protect the weak and maintain their beliefs.
Released as part of the Target-exclusive Reveal The Shield subline, this Tiny Turbo Changer 3-pack contains a redecoed Optimus Prime and Bumblebee (in their first non-blindpacked release) and a new Steelbane figure. This version of Optimus features red wheels & Tech Spec-esque patterns on his robot mode chest and... groin-flaps, though the real decoding is on his vehicle mode roof, which when seen through the attached clear-red weapons (or similar plastic device) reveals... an Autobot symbol. Surprise.
The Premium Series Optimus Prime is both a retool and a redeco of the Leader Class Optimus Prime toy. The major selling point is a more movie-accurate headsculpt with longer ears and detailing based on the final CG head design, and a flip-out energy sword to replace the ion blaster that was included with previous versions of the toy. A smaller laser is seen when it flips out with the sword. This energy sword is detachable and attaches where the Ion Blaster did, compatible with non-premium Optimus Prime leader class based releases. Because his ears are much longer, the truck roof panel that hides his head now has two holes cut into so the head can fit inside the cabin.
In "Transwarped", after Sari realizes that she is not human, Optimus attempts to have Professor Isaac Sumdac and Sari reconcile with each other. Later, they encounter Masterson, who is piloting his headmaster unit on Starscream's decapitated body. He defeats Masterson by tricking him to transform into vehicle mode, which was impossible due to with the Headmaster unit on Starscream's body. Later still, during a melee with a rock creature that found its way to Earth when Bumblebee returned from his accidental transwarp, Optimus struggles to stop Sari, who goes out of control after using her key to upgrade herself.
Megatron is captured by the Autobot Targetmasters in the episode "Do Over". When Optimus learns Megatron has been captured, he rushes to be the one who kills his old enemy, despite the closing launch window of the Ark. When confronted by Optimus Prime, Megatron attempts to use the Autobot Targetmaster Nightstick to shoot the Autobot leader, but Nightstick takes control of Megatron's arm. Megatron then tricks Optimus into using Megatron's own sword to cut his hand off, freeing him from Nightstick. Optimus fails to kill his foe and misses the launching of the Ark, which has been taken over by Rodimus. He then takes out his anger on Blurr.
Nonetheless, I remain a big fan of Lego and although I think they have somewhat moved away from their roots with the excess of licensed products (and the earlier licensed products were, in my opinion, not very good because they contained too many specialized non-generic pieces that weren’t useful for generic building. But that situation is improved and in particular we have found the Star Wars sets to be of most value for generic building, because they generally have very few really specialized pieces (although to be fair the sets are most useful for building other spaceships, etc).