There should be punishment for time wasters more specifically when you are selling / buying a vehicle.
Every time someone wastes your time it costs money to re list. They should have to pay for the re list charge at the least. If you change information on your insurance details you are charged an admin fee, this should be no different.
That would make people think twice about being a time waster. There should be a 2 hour cool down period where they can opt out. after that they are charged.