Sadly these days most Amiga games are not worth much. It is common for most games to be found on ebay selling individually for £0.99 or as big lots of 20+ games for under £10. But there are rare exceptions that do still attract collectors and command much higher prices.
At the moment a mint condition boxed copy of Moonstone is selling, and has so far reached £66 which is very high for an Amiga game, original and mint or not.
Are there any other Amiga games you have seen sell for a high price? Or do you know of any Amiga games that are now rare and as sort after?