Sounds like money laundering to me. Especially given that the price of the item he inquired about was insignificant compared to the amount of money he wanted you to handle.
A new ploy for fraud?
I recently got an inquiry on one of my ads (not here on Audiogon but on another site) for a pair of interconnects. After a few emails back and forth, we agreed on the price of $90. The prospective buyer then said he is in England and would like to propose an (unusual!) payment method. He said someone in the states owes him $3000, so he will ask this guy to send me a check for $3000, I am to cash the check and then WIRE him the difference ($2910 in this case). Of course I said thanks but I deal in cash. I never heard from him again. Has anyone experienced this?