That said, I would need to see the prices come down before I'd consider using it. I see the Signature Shirt is $12. For comparison, I recently purchased 6-pack of blank t-shirts [1] for $21 ($3.50/shirt), and found them to be excellent quality. I've ordered similar packs in the past for similar prices, and have always received high quality products. It would be hard for me to justify spending 3-4x per shirt AND a $70 annual membership on top of that.
Without the membership fee I might consider it, but I think it's simply too expensive as it stands. I do think it's a great concept.