I wonder how many of those games are actually commercial games at all - lots of them look like coverdisk demos of the games. For example, check the HOL disk scan of Tearaway Thomas
http://hol.abime.net/1326/diskscan and compare it with the EBay auction. Nothing even remotely similar.
I realise some different versions exist so the disk scan maybe off another version, but if you compare a disk scan of Amiga Power issue 18 with the 2 bottom right disks, it looks identical. Therefore I think the guy is peddling coverdisks as the real games - the only originals are crap like Workbench 1.3 from the Starter Kit and the fact they are "original" coverdisks...