As he is no longer with us you may find the family or whoever now holds the rights are running prints off.
I myself own several pictures from various artists purchased off ebay, amongst them I own three Carless, and the original of a Chinook Christmas card used once by the benevolent fund. The card one was purchased from the artist and the Carless were sold by someone who didn't know who he was or what they were all for a very very good price.
so I wouldn't write evil bay off as a source of art.