Craigslist scam. Offering to overpay by certified check for an item that can not be shipped.

I received a message from this number to overpay for an item posted on craigslist.  What is the meaning of this?

Craigslist scam. Offering to by certified check for an item that can not be shipped. Says when check clears, will have mover come pick up item. Why not send mover with cash?

Offered to pay me $2500 for a $750 item, and that after my check cleared %100 would send his mover to pick up the item. Actually sent me a check from a Jones Law Firm in NC, whom I contacted and the check was never issued by them. Total Scam. Reported this number to the Los Gatos, Morgan Hill, and Gilroy California authorities as well as his return address which I'm sure was no doubt a fake as well.  The return address was from a company in Burbank California called Trainevision.