Federer's T-shirt which he wore when he won his first (perhaps only) FO title , went on sale today in Abudhabi for appx US$45. I just bought 2 of them size XL. Will this T shirt be a collectors item in the near future, and how much will it be worth. What if i get Fed to sign it while he prepares for US Open , next door at Al QASR hotel in Dubai. What will its value be then.