50p sounds like a manageable (i.e., small-enough) sum; I'd consider buying one even though I don't forsee a practical use (attendance at any pertinent event) in the near future.

(I do fear losing the badge before ever using it, but perhaps that could be preevnted by burying it at the bottom of the pick-box in my guitar case.)

Would you accept US currency, or a check in US form, at your Doncaster address? If so, how much should I send in dollars-and-cents for the 50p-plus-postage? Or, would direct payment to Max at Mudcat Cafe HQ in the US, plus a letter (or PM) to you in England, do the trick?

I can see that round badges (as opposed to the standard-format little rectangles designed for insertion into cheap little standard-format plastic holders) would not be easily produced in the "do-it-yourself" manner I had imagined.

I'd just be getting the one ~ no fellow 'catters in my immediate area...