My neighbor told me about these sites he read about in the Times that are sort of like Threadless but for emerging artists or cheap prints that start at $20 and up. A fun and easy way to splash those baron walls if you are young and struggling to sell or buy art. See 20x200 and UGallery.com. Below: Crystallized by Michelle Hinebrook. (Thanks Phillip)
* From the comments, Shawn suggested Steadyprintshop.com as well. Below: Work Hard For Satan '10.