I suspect that we have all done this at some point in that we have been to a show and wandered round the stalls and seen something of interest and its in the back of you're mind that you should buy it and you didn't. Looking back be it days, weeks or years it still grates that you didn't buy it. What is it and when?
Mines Ferret related it had to be didn't it; Ferret rear mudguard on Marcus Glenns stand at Stoneleigh five years ago at £45 nos. It still grates it really does peanuts thinking about it now suspect I ran out of pennies.