I'm about as new at this as one can be, so apologies if this is a dumb question.  Many providers offer "incall" at hotels.  In those cases, is the hotel's room charge included in the provider's fee, or am I expected to pay the provider fee plus the room charge?  Thanks.

If it is advertised as their in-call, it is their cost.  They get value from in-call by being able to see more clients with less hassle.  Also safety.  Plus they know what the place looks like and can minimize exposure to police setups.