box of sand

In a fraudulent exchange of goods, term used to describe a worthless decoy object delivered in place of what was advertised. Originated from a number of eBay scams involving a seller offering expensive, heavy items (such as computer hardware), and ending with the mark being delivered a box filled with sand at their own cost.

"Wow! So all of this premium home theatre equipment in the back of your van is only $300? Tell me, is that box of sand compatible with HDMI?"