sex is overpriced in America. Blame it on its illegal status.
I think for this older contractor guy its also about the power. He probably enjoys the thrill of making regular college girls become whores for him. $ 800-1000 for just a night of sex is ridiculously expensive no matter how hot clean the girl is. Besides cleanliness of girls is only relevant if they offer condomless sex. Men like him retire to countries like Philippines and Thailand where sex is cheap.
In Pakistan it is possible to lure house maids or other low paid working girls. It is possible to have a soft-prostitute experience.