They used to sell prints on Renderosity but I don't think they sold very well. The thing is, you would be selling art prints to artists here....what you want to do is sell art prints to a wider audience, I think. In the upcoming Renderosity Interactive Magazine, I happen to know a book on marketing art is being reviewed (Hisminky has written an ebook and a sequel on markets which is available in the Marketplace, and webpage might be worth checking out for ideas). You should contact the magazine if you have an idea for an article....email your ideas to mag@renderosity.com and they will get back to you.