I wouldnt even take a phone call from the guy at this point. When i sold my first TT, the fellow and i went to his bank and the teller generated a check in front of us. I signed all the paperwork with her as witness and the buyer and i went back to my house to take possession. I helped him hook up and followed him home, Just In Case as he was worried that his SUV didnt have the towing capacity (my TT was 1000# lighter than the one he towed regularly, but that didnt seem to register with him).
Take your time, your buyer is out there.