That's a heck of a cool idea, nice job! I visit a lot of t-shirt sites and my first thought was "Very clever!" which doesn't happen that often. :)

My only problem is that I already have enough of a t-shirt buying habit that spending $25 per shirt isn't going to happen very often, especially when I don't know the quality of the shirts. You might add more detail on the actual shirt quality and fit.

The email collection line on the homepage doesn't make it clear what kinds of emails you'll be sending. If it's a weekly (bi-weekly, whatever) showing of the new shirts I'd say something like 'Sign up for our weekly new shirt email' so it's more specific.