i have intermittent luck selling prints on ebay.
others have had "a following" there so they kept
selling to the same 4 or 5 people over and over again.
i also know of people who have had better luck selling on etsy ...
but for very little $$
i have had better luck ... selling on imagekind.com ...
but they do all the printing framing &c ... it is sort of a give and take
i make the prototype image and they do the other stuff i can't talk about here on apug ..