Toktogul, I still don't think you understand. I didn't even necessarily mean reselling, though that is still kind what you were doing.
As Arkhan already said, people need things now for some reason. You accelerated demand of the game, by buying it right away for those people instead of letting them just wait it out.
Regardless of whatever "good deed" you did, you have to realize something.
As an individual buyer, you have bought not one, not two, but three copies of one of the most popular games ever made for the PC Engine.
Every person, collectard or gamer, contributes to the overall problem. You can't blame other people if you do the same thing.
It is surprising how much the price has jumped for Rondo, it used to be in the $100 range. But things just happen.