@BoingBoss I find you answer stunningly insightful... although I'd say I've seen the 1200s more often go for somewhere between 100 to 200 dollars usd... that might be from looking at 1200s without mice or psu's... the value varies a lot between America and UK (maybe most of europe too) because america had a lot more people buying the big 2000/4000 boxes for toasters, and relatively people few buying the smaller wedge machines or even 3000.
Yes, it is most likely worth taking atleast a couple good pictures of your item for ebay, and gallery's not a bad idea either because it shows up in refined searches, same as having a buy it now option, and Amiga in the title, since I personally look for amiga stuff by simply typing 'Amiga' and I'd bet a lot of others do too... don't get discouraged if there is initally only a couple bids, e-bay auto sorts by ending first and people like to wait to bid, so you get more bids towards the tail-end of an auction (oh and some people 'snipe')
ed: and if the item's truly valuable, it could be better listing it twice and waiting for bidders than to start far too low and risk only one bidder paying next to nothing... though that probly doesn't happen too much...