Haven't a scooby doo where you guys are looking but on eBay UK (which I check every day) Amiga games very rarely even sell at just 99pence boxed or not...
Most of these games get re-listed time after time without any takers (often wonder why the sellers do it) and very rarely do you see a game selling for more than around £20...
Current List Of Amiga Games On Ebay UK...
