That is probably the most annoying thing someone can do is waste your time and make you rent a truck just to come down and see him going though everything that he is not going to sell to you now.  Feel like he wanted to use your truck to move the stuff and not actually sell it to you, not sure how he was planning on pulling that off but people are nuts lol.  Anyone who wastes peoples valuable time like that are just inconsiderate as you could have been doing way more valuable things with that time instead of wasting it on him.  Glad you took the high road and just left karma will come back to get him probably just like you said he will most likely default on the unit and someone will get a great bargain when they buy the unit at auction.  Maybe you should ask the storage unit manager to inform you when and if the unit goes up for auction, might be able to get a sweet deal out of it if you can win it if he defaults.  That would be satisfying to win the auction at a lower price than he would have gotten if he just sold it to you like he said.  Load it up while he sits there and watches you as you paid a fraction of what you would have given him if he honored your deal.