Your rant seems justified to me. She really should have done her research before selling. One time I saw an ad for 2 Schwinn Travelers for $15.00 each (I think, it's been a while) to be sold at a garage sale a couple of days later. I asked if I could buy them that day for full price and pick them up. The seller said yes and I arranged to head over right after work. Before I was done working I got an email stating that there was more interest than expected and she would be taking "bids." A couple days later I got an email saying they were up to $140 for the pair and asked if I wanted to make a better offer. I did not reply.

There is one thing she did that I can understand as a seller. I never take an ad down until money has changed hands. This gives me backup buyers in case the first deal goes through.