Because if hookers had business savvy, they wouldn't be hookers very long.

If a normal person needs to make quick cash, they tend to offer themselves, their services, or their goods at a much reduced rate to get the cash quickly.

A whore under these circumstances will ask herself "how can I get the $500 I need as quickly as possible?" A light bulb then turns on over her head. "I know! I'll raise my rate. Guys will think I'm exclusive, and even though my phone isn't ringing at $200/hour, it will certainly ring at $500/hour."