I buy and sell quite a bit online, and here on the FordBarn I mostly buy. I have been burnt... One fella sold me a "set" of 8 connecting rods. He only sent 7 and said with the great price I got on the parts I should just live with it.
Another seller sent me a pack of 8, Autolite 46's, still in the boxes!!! LOL they were all used spark plugs.
BUT! Last week I purchased an exhaust gas analyzer and an engine analyzer together from roysboystoys and I am very happy with how that went.
I get tired of it, but as most swap meets tend to dwindle in size and therefore parts availability, buying parts online has been the way for me to go. eBay has become so lopsided to the seller that the buyer is trusted 99 percent of the time. While this helps larger businesses and those selling "new" items that the masses consume, people like us who try to move items in a niche market can really take a beating. I sell quite a bit on eBay and the buyer is usually very happy with the transactions. I do ok.
Enter the FordBarn... I sell the CD's and Thumbdrives that contain a plethora of parts manuals on them in PDF form. I have sold very little however. When I do list parts, I get very little to no contact. It would be interesting to know the statistics for how many times the website is visited each day, how much your post visited (if at all), etc.