U2 Photo

[Robspro]

Hi everybody,

I have had for a number of years an Island records 8 x 10 black and white promotional photograph of U2 signed by all four. If it is legitimate(which i hope it is , i have no reason to doubt) how much would it be worth roughly? I paid around £60 for it 2-3 years ago and when i look on collecting sites for a price comparison get some pretty varied results. I don't want to part with it, but i am interested to see if it might have been a good investment.

Regards

Rob