Keep in mind that by the time you spend a lot of money on an A500, you could have bought something more expandable, more capable or both. If you just want to play retro games, don't spend any more money, you have it right there.
... The issue is, once you start down the dark side of the Amiga Experience, you will be switching, changing, collecting, upgrading for the next 30 years (or is that just me?)