So lets say there are 2000+ A500 and up machines and you could somehow target them so most get notified.
Then lets say you can sell your game to 500 of them at about $15 (£10) or so..
$7500.. Assuming digital release, all 1 person and in their part time... Not bad..
Still not sure anyone is going to quit their day job, but might get some people seriously interested in developing good products..
Of course, the hard part is, even knowing the audience might be larger, how many of them would be willing to buy a new game? Some (many?) people are into Retro only for what it reminds them of... Even if so, how many of those would be interested in YOUR game?
I think 200 is low (if marketed properly and there was a good way for someone to purchase), but I'm also not sure if 500 might not be too high...
It's hard to tell tho, because you KNOW there are more Amiga users than on the map even...
It's an interesting question...