i dont know if this has been done before or what, but on a forum my husband frequents they have a trading post. if you have something you havent found a use for, or if you've upgraded and want to get rid of the old one, maybe someone here might be able to find a use for it.
Rules: first post item you want to trade or sell.
then post item or price you want for it.
if someone decides they want to trade or buy they will PM you.
once you agree to trade all details will be worked out with PMs.
when you have come to an agreement announce that your item is sold.
example:
WTT (want to trade) KA mixer (XXXwatts used once and was given a better one for a gift.) for a three pc. set of heart pans (6", 8", 10" preferred) or $XXX.XX
(this offer is just an example, i dont even have a KA mixer)
That would be great, but the CC rules state no soliciting and I think this would be considered just that. You can always put it up on ebay.
no wonder a search didnt find anything like this on here before. sorry 
I'm not 100% though, maybe one of the moderators will pop on and clarify the rules. Don't be sorry, it was a great idea! 
Here is a thread on that exact topic. I think it would be a great idea, but I can see the administrators point.
http://forum.cakecentral.com/cake-decorating-ftopict-197941.html
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