There is an advantage of the A2000, you can switch off the expansions and run everything that runs on an A500.
That is the advantage of the 2000, but like said above here, most games will also run in WHDload on a 3000/4000.
Either way, it's going to cost an insane amount.
Going for a Blizzard 2060 or Cyberstorm PPC is like spending a month salary for most of us.