On their site, you have to allow the script from shopfactory.com as well as their own. Did you do that? I didn't have any trouble adding it to a cart and getting as far as the checkout window, though I didn't actually place an order.

That said, their FB page hasn't been updated since 2011, and there are links on their homepage to a Strava competition also from 2011. So I might be a little hesitant about putting in payment information without verifying they're still there.

Why not email them directly?