Folks,
I’ve been buying train-related items on Ebay for many years (I am not a seller) and its one big example of caveat emptor.
I’ve had virtually 100 percent success as a buyer and from reading this thread that seems to be the case (or very close) for many others. The one bad one I had was a tinplate crossing signal that was DOA. Seller returned my funds, no questions asked, within minutes after I sent an email.
I have no special advice that hasn’t already been mentioned: read descriptions very carefully, check feedback, and ask questions if needed.
Btw, see a lot of this these days: “I’m not a train expert…” and “…not tested…” and “…pictures are my description…” When I see those I quickly move on. Those are red flags for me so no sale. There are always other sellers with the same items who know how to effectively craft a for sale listing.