IMO, you ran into 2 issues: Your prices weren't competitive, and your payment methods were confusing and convoluted as hell. The first one doesn't seem so bad now, so if you get a simpler payment method, and reopened this project, you'd prolly get some sales with no problems.
Actually I think that this was also caused by lack of any ads.
And I can't imagine what can be easier than paying in BTC. It's even much simpler than some of our competitors :)