Not legal in the FAA' seyes. This is a private, not a commercial pilot. A private pilot cna share expenses, but under a very, very long line of Chief Counsel and NTSB decisions, in order to share expenses, the purpose of the flight needs to be shared. That means, at the very least, that the reason for flying and the destination must be the pilot's.

The scenario makes it clear that the reason for the flight is the passenger's. not the pilot's. IOW, the pilot was not going to go up and the air and fly over a bunch of properties anyway and the salesman just happened to come along.