Make the guy an offer, he takes you up on it and you quickly withdraw it.
This was Matt's prerogative, given it was Matt's unilateral offer. Joemoney did not accept the offer (#msg-517961). He indicated he would accept the offer at some future (undefined) time. This is not the same thing as acceptance. If Joemoney had actually tendered payment, i.e. "consideration", and Matt then withdrew the offer, that is another matter. (Basic Contracts -- Business Law I)
p.s. Please remit one pack of cigarettes in payment for this Jailhouse legal advice. <g>