What's the deal with the U2 Vertigo tour shirts? I'm going to see them live towards the end of this year, so I have no idea how much they cost at the concerts. Anyway, on eBay, they're going for almost (and sometimes more) $200!!! What makes these shirts so special?? Does anyone here have any of them? And, btw, how much do they cost at the shows? Thanks for the help.