At the risk of stating the obvious ... well maybe not so obvious to many ... travelling to her in-call location, showing up at her place without knowing what the deal is, is a fool's game.

How much stronger position is she in to ask a high price after you've gone through the time and effort to get there and she's done nothing?  How likely is it that after doing all that, a potential client is going to walk away if the price is over the market?   If you've read reviews, how many guys show up and go through with the session even after realizing the girl is not close to her pictures, much less charging an exorbitant price?

If she hangs up when asking the price, you have just saved yourself money better spent on a better provider.

"How much do you charge" sounds like a cop's question requiring an incriminating answer..

Try saying this:  "I've got $275 on me.  Do you think we can have a good time for that?"

There's no substantive difference, but sometimes a provider will feel more comfortable with the lower-key approach and be willing to give you a simple yes or no answer.

Another poster here has an interesting technique for this

If your not sure what the rate is, his strategy is to open the bidding low, and see how it goes. Instead of saying, "Hi, not sure, but I've got 275 clams, think we can cook something up?" Try lower and see how far you get, "Hi, I've got 100 roses today, can you help me arrange them?"

Never tried this myself, the deals I've had when I've had to ask, they've told me without any drama. Usually, the lady will be the one who brings it up when you call her to set up a date.