Negotiating is good
 

Too many guys react negatively to girls asking how much up front.

Put yourself in their shoes and realize that when they ask, it's a genuine opportunity to see what all is on the table exactly.
And if you offer a little more than they ask, the doors tend to open and the panties have a way of flying off faster.

Don't be shy.

It's their culture. Americans are the only population where negotiation does not take place on this planet.

Best way to negotiate a simple h j is to stick with the going rate of $40. If they demand 60 just tell them no thanks, "massage only"! At this point more than likely they will cave and take the $40. If they don't, enjoy the massage and tip them $20.
If a girl is FS, use this site and pay attention to the tip of the average customer. No need to negotiate when you have a cheat sheet