It's the same phenomenon as slapping a tag/label/logo on a pair of jeans, or a handbag, or a car, and then doubling the price. People start to associate the logo with "Expensive", hence "Exclusive", hence "Denoting Status". Of course, porn whores themselves are particulary succeptible to this type of status-symbol branding.

And, yeah, for the cost of an hour with Candy, you can go on a week-long binge with college craigslisters/local strippers/telemarketers from the office next door, with enough left over for an assortment of lotions and creams to ease the burning afterwards.

I guess that, to the civilian, the appeal of the porn escort is bragging rights. It's the civilian equivalant of Kurt Lockwood:

FUCK ALL YOU MOTHERFUCKAS IM OFF TO THROAT-FUCK DRU BERRYMORE ILL BE SURE TO SAY HI FOR YOU WHILE I AM PAINTING MY LOAD ALLOVER HER FOURHEAD. I M ONE OF ONLY 20 PEPOLE ON HER XCLUSIVE CLIENT LIST SO THAT MAKES ME MORE OF A SPECIALIST THAT A BRAIN SURGEON WHO ONLY OPERATES ON ROCKET SCIENTISTS!