Propose a 15-minute coffee date at a place walkable for him. Buy him coffee and pay him $50-100 for his time. If he's "fake", he'll probably say "fuck you" to the offer. If he's real, the cost of the coffee date will seem inconsequential to what you spend later!
Admittedly, he may still reject the coffee meet even if real. Several possible reasons for that, some good enough, others not.