While this kind of scam is deplorable, if you fall for it, you only have yourself to blame. When you're asked to deposit money into an FC chest, with naught but a promise from the other person that the agreement will be fulfilled, that should be a red flag right there. If you still deposit it, yup, you only got yourself to blame.

Buy and selling plots on the market board would be a good idea, but not for the reason you describe. People really just need to use their brains more.