....But I will NEVER buy a truly used one where the seller has NOT tested it, such as from an online antique dealer or estate seller who knows nothing about trains. Words like "looks like new, but I have not tested it" and I move on. A new one in the box from such a dealer is probably worth the chance, but only if the price is right."
Exactly what I was talking about: A Lionel GP-9 6-18567 was listed on e-bay, at a very good price. The listing said only that it was used, and then (all caps) BOX-MISSING-FLAP. The standard e-bay explanation of "used". Nothing else. Except that used items cannot be returned, and are not tested.
I sent TWO e-mails to the seller, asking a simple set of questions: does it run? and do all TMCC features work? Never got an answer either time. Without that information, I had to assume that it did not run and that the TMCC features did not work- so no bid from me.
It sold for just over $100. Testing and better information likely would have gotten a far higher price (and certainly a bid from me).
Sellers, you will make more money if you ARE thorough and if you simply test items on a 30" piece of track with a transformer. Otherwise what you sell are basically "parts" locomotives.