Dang, I wish I could find someone who is basically giving away arcade games...

How well do you know the guy? If this is just a business venture for him, and he says 75 each, then offer him $100 total and see what he says. The worst he can say is no, and you still get them for $150. Odds are, he just wants to ditch them at that price.
Haggling, it's a wonderful thing.