Because when a more or less working 2.5mb A1000 complete sells on ebay for £44 you have to wonder why.
I would expect a working A1000 motherboard alone to be worth this much but obviously it isn't or perhaps ebay is a complete waste if time.
eBay is a crapshoot when you list an auction. A pretty vanilla A4000 recently sold for about $480, which seems rather high.