The problem with games like FF 7, isn't that they're rare, but that most of the copies are in the hands of people that actually want them and have no intention of selling them. Same thing with Symphony of the Night on the Playstation. Contra for the NES is common as crabgrass, but back when I used to work at Funcoland, it was far more expensive than just about every other NES game because very few people were willing to sell their copies.