Depends who is the buyer. I know a ton of people over the years that paid too much for a title. Simply didn't do their homework. If they wanted the game NOW and money is no object, then the seller is in a position to set the price. Most salesmen work in this manner.
The market is increasing for high quality machines - not confined to "A" list titles. SS and EMs are starting to creep up again. Poor conditioned machines are dropping in price.