Itís a mixed bag, so it comes down to who youíre dealing with. Some etailers like Smokingpipes.com do a complete and through clean-up and sanitation, they donít try and hide anything and their descriptions of condition and measurements are accurate 99.5% of the time. Of course you pay a bit more for their services. Ebay is a crapshoot, their are a few very reputable dealers and more than a few whoís business practices are questionable at best. It is possible to get a deal on eBay but you do need to do the research and count on doing your own cleanup.
Generally the estate market is about 1/2 of what the pipe sold for new, depending on condition.
My advice would be to stick with the etailers until you have a chance to figure out whoís who on the bay.
If I see a stick that made a noob nic sick,I put it on my list as a must try. (UBC03)