Fraudsters out there! Beware.

In the process of selling my cdx, on hififorsale,& pfm I encountered someone who offerred me over the asking price to hold it until he returned from holiday. He then told me he has sent me £4k, to cover shipping, & I was to send the excess back to him!! I got the distinct impression that I was going to be fleeced to the tune of £3k or so.
I'm sure that others here have reported this in day gone by, but the scam is still out there. Beware. If it looks too good to be true, .........
matt.