I had an A500 and A3000 new back in the day (still have the A3000).
If we could find Toaster sales figures you can easily figure out the minimum number of A2000 sales at least. Just about every TV station had at least a pair, as well as most cable systems. Also, the A2000 was used by Prevue for cable system program guides, so that could be thousands.
My local cable provider Time Warner Torrance only recently swapped their community channel (normally an informational slide show with background music) from an Amiga system to a Windows system. Now I get to see application errors instead of guru's...