>>23427399
Even ignoring how fucking stupid the whole "4chan is a community" argument is, nobody is going to sell an effectively "mint" collectible at a third of its going price even if they were next door neighbors.
>But it retailed for like $20, why's he charging $100 for it?!?!?
John Bandai sells a Gundam and they make 100,000 copies of it and sell it at $20. They know the Gundam sells well due to high demand, so they make frequent batches of it so stores can keep it in stock regularly. Because of high demand and a high inventory, the retail price on the Gundam stays even.

John Bandai then decides they want to promote their new anime, so they make a 100,000 AMAIM kits to test the waters and sell them at $20. Nobody watches the show and the kits sell at a snails pace, and stores start slashing the prices down to the single digits. Because of low demand and high inventory, the price on AMAIM kits is lower than MSRP.

Later on, John Bandai decided to make a kit for a then-new Gundam show and sells it for $20. The kit proved popular with kitbashers and remains one to this day, but not popular enough for John Bandai to regularly reprint. As a result, the kit is regularly sold out at all the stores. Due to high demand and a limited inventory, those who still have the kit are welcome to charge how much people are willing to ask for it, and as supply of the kit decreases, the price increases.

Supply and Demand 101.