If the lady's rate is $500 for the hour (and I would use her ad or website as the determining factor, not the TER rate listed on her profile), then that's the amount you pay the lady for an hour. You do NOT negotiate the fee (frowned upon by providers) NOR should you give the lady more money (frowned upn by hobbyists) The money paid should be constant; You are paying for her time only.    

Now, what services YOU get in the hour depends on the flow of the session. It is all variable; all you are doing is paying the lady to be with you for the hour. While another hobbyist may have received a shower, a massage, BBBJ to completion, some rest, follwed by round two doggie, some rest, followed by round three anal; does not mean that this is the menu you will receive. Now you can certainly expect to receive some combination of these services if the reviews reflect as such. But once you and the provider have established a comfort level with one another, you need to guide the lady as to what services are important to you. She will take your lead. Each hour flows differently, so you want to make sure it flows to your liking.

of variables.  For example if your hygiene is not up to par, do not expect BBBJ.  Some guys can get the first pop in the first 20 minutes and therefore have time for a round 2.

Sometimes ladies will ask a client during a first session, "What do you like"?  That is your chance to try to try to plan the menu for the day.  Remember, YMMV is always appropriate.