Cheese Sandwich (joke)?

A guy walks into a pub and sees a sign hanging over the bar which reads:

Cheese Sandwich: $1.50
Hand Job: $10.00

He checks his wallet for the necessary payment, then he walks up to the bar and beckons to one of the exceptionally attractive blondes serving drinks to an eager-looking group of men.

"Yes?" she inquires, with a knowing smile, "can I help you?"

"Yep, I was wondering," whispers the man, "are you the one who gives the handjobs?"

"Yes," she purrs, "I am."

Replies the man, "Well, then, wash your hands because I want a cheese sandwich"