I usually count out the money in front of the buyer so he doesn't need to. That prevents me from accidentally shorting or overpaying, and it relieves the seller from having to ask.
I once was in Minnesota and agreed to buy an $11,000 item from a guy there. He told me, "Just take it back on the plane with you and send me a check when you get home." I thanked him but told him I didn't want to carry it on the plane....so he mailed it to me and I mailed him his check and we were both satisfied. The point being...it sure is nice when two upstanding people do a deal.
As for the OP's story, I agree it was an attempted scam.