Have the buyer wire funds directly into your account.  Only upon verification of money received can he take item.  Or you can have him give you a personal check, but it will take awhile for the bank to make sure he didn't stop payment or the check bounced.  Hold the item for a week or so until you make sure check is good.  I normally have had good luck with farmers but have had one instance where the farmer stopped payment on an item after he picked it up.  I did get item back, but lost a sale.