I saw one with a solitary Dunn signature on it go for £47, but arguably it was a nicer shirt being one of the red and black away ones but whatever, if you offered £50 for it that would be an instant buy out. Just tell me what you'd realistically be willing to pay for it. If you're prepared to collect it from a BB1 address also, I'd be willing to lower the fee.
Edit - Just realised you're in New York. I'm guessing you might struggle to collect. I can post it however.