This is a really cool shirt, but I have some improvements that you might be able to take into consideration!
I've noticed that the fashion trend as of now is pretty simplistic. People don't really like to buy things that make them stick out. Maybe if you could make a small rectangle around the bitcoin logo and keep everything in that rectangle the same style (the mixed paint) as the rest of the shirt is and then make the rest of the shirt plain white, you might be able to get a few more people interested. If there are changes in the shirt, let me know, I might be interested!