Amazon is very easy to list books on. Their charges are quite high so the price needs to be loaded somewhat, but buyers seem prepared to pay the extra. Amazon has a reputation for customer service as well.
Greenmet is easy to list on and many of the ebay sellers have migrated to there.
Ebid, which should be a natural and obvious place for the sellers to migrate to, still has a very low profile, many of us spread the word, but it's only small publicity.
I think, and wish the management did too, that the time is ripe for a publicity push, an advert on ebay itself might do the trick. Wouldn't that be fun!
http://uk.ebid.net/stores/Gyronny-Books