how much for the one on the right?

Well, there you go, then. From the Las Vegas Review Journal:

Talkin' Dirty
Sex industry is topic at convention

By DAVID KIHARA

Wearing a T-shirt with the words "Will Work For Sex" on the front, Robin Head stood outside Palace Station and proudly said that she worked in the sex industry.

Head, who said she was the former owner of an escort service in Houston, was among 150 sex workers, business owners, academics and social workers who gathered in Las Vegas this week for a convention that brought prostitutes, pimps and professors together to talk about the sex industry. Read more.