I assumed you meant "modding" as in modding(..?).
The A500 is big. Steals alot of space. If you just want to play old games, then I'd reccomend UAE (emulation for x86), which can emulate the whole range of Amiga computers, support all Kickstart versions and provide virtual memory expantions. Some games work with a perticular kickstart version, some a special chipset, with or without expantion memory, and some are just generally bitchy.
It's a whole lot easier when expation memory is just a mouseclick away.
If you just want the better specced Amiga, no matter the cost, then wait for AOS4 to be released and buy an A1. It's a fairly modern computer by all means (PPC G4) and it will have the snappy AOS in it.
-Very much unlike f.ex. windows which potentially would look sluggish even if it was plugged into the worlds collective computing power.