ok thanks for your replies, as i said it was just an quick thought.
although because the tartybike boys would know a lot more about the parts than just riders, i thought that they would be able to tell by looking at 2nd hand products to say whether they are worth selling or not, like obviously not buying a pair of cracked forks, but scratched products wouldnt really matter.
although this could mean them getting conned out of money i guess, so this may not work.