Actually, I do - quite frequently.
I buy and sell regularly on eBay. It allows me to get many items I want at a reasonable price and a means of moving those I'm not so fond of. In many instances, I buy lots of built or 'junkyard' models and parts for a few specific items. When reselling unneeded builts or parts they're always described acurately, including faults. Many have been listed as out-and-out glue and paint bombs, poorly built, with missing or broken parts. Oddly, those are sometimes older models or specialty parts and occasionally bring more than the better built ones.
While I have issues with several listings that are less than 100% honest or accurate, and dislike many of eBay's policies, it remains an excellent venue for my needs - not only do I get many of the kits and builts I want, but they have now become 'in the black.' I've made more on eBay than spent, so my entire collection is - at the moment - free.
I am, by the way, familiar with the Seller referred to here - he has contacted me in the past in reference to lots I've listed with offers to purchase; however, I start my items quite resonably (in my opinion) and he typically offers about 40% of start, which is his prerogative. We have not done any business.
Interesting thread.