The Hard Rock Cafe version of the Music Rising shirt is slightly different--it has a Hard Rock logo on the back up near the neck. It's $6 cheaper from them, but I'm not sure if it's the same quality shirt. The u2.com one is Edun and is really soft and of a nice quality.
U2.com still has MR shirts in every size in stock. Don't they take euros? You don't have to be a member of the fanclub to order from u2.com. I don't know if you'll be able to find one otherwise--they're not showing up on ebay.