The scammer will ask you to put an item in your Play Wild My Shop then claim that they won't buy it, they'll just try it on with the dressing room feature. They will then buy your item and leave.
The scammer will sometimes claim that they have little to no gems/sapphires; therefore aren't capable of buying it, which is a lie.
How To Avoid This Scam
Don't listen to the people who will claim they "won't buy your item". If anybody says that to you, lock them out of your den then block and report them. Exposing them or adding them to this wiki might also be a good idea.