I recently bought a PS2 because the used ones were selling for $99. $99 is easy to rationalize to my wife, because it just doesn't seem to be a lot of money (especially since she can easily spend $100 on a manicure, haircut, or new pair of shoes).

Of course, the hardware isn't the sticking point. it's the software. I feel a lot guiltier when I plunk down $50 for a game than when I plunk down $200 for a new video card or hard drive. It's one of the reasons I bought a PS2 -- I can buy used games for about $10 that I would never have gotten to play otherwise (Kingdom Hearts, Metal Gear Solid, SSX, Jak/Daxter). It's much harder to find older PC games at the same price point at a local store.