I'm surprised no one has questioned whether or not the booking will actually go ahead. I personally would go ahead and endure a client like that for 3.5k, but i would be very suspicious. It's clear the guy likes to play head games, so i wouldn't be surprised if he's stringing you along with the temptation of a motherload only to block you after you take a flight and have your time wasted. If something seems to good to be true, it usually is. Be careful, get a deposit up front.

Reminds me of a head fuck ex reg i had. He paid well and my strategy was to treat a booking like i was doing a case study on a narcissist!