Quoted from KISS73:
Why is everyone asking almost new price for these use pinball machines? Just a few hundred dollars more and you can buy new.
It depends on the title, the condition, how desirable it is, and how rare it is.
And yes, sometimes people price games well above the going market price. Sometimes people add a whole bunch of mods to the game and then ask a higher price because of the addition of those mods.
Then you also have retail pricing from retail shops that repair/refurbish/restore and resell older games, though it also usually includes a warranty of some sort.
Then there's ebay, where prices are just ridiculously over the going market prices.