I must agree with you that it'd be nice to have a trading place for such activities. On eBay everything that says Tumi even if it's a used and disheveled item go for much higher price than anything else. Plus Ebay takes a lot of money from sellers. Lastly, you can't trade anything, and these people don't take care of their luggage like we do.
You can also do a national search for Craig's list.
https://www.google.com/search?q=crai...w=1251&bih=890
come to think of it, I need to clean out my closet also......