I'm sorry to hear that. I think decent A2000 mainboards might just be hard to come by and fairly coveted these days, so patience is useful. I've been fortunate enough to find two Amiga 2000s via craigslist over the past year, so I'm starting with those.
One is in very good condition considering, a rev 4.2. Minimal corrosion reached a few vias, but it doesn't seem too bad. This is my current build unit.
The other is a 2000HD, but it is in pretty rough shape. Corrosion has proceeded fairly far along the traces and into various sockets. By appearances it was probably stored in some inclement/damp conditions as well. (For shame!) This one is flaky at best and presently shows only a black screen, so it should be a good project for someone with patience and skill. (The board is a rev 6.2, so that's a tempting pay-off.)
Cheers,
Kludgy