It is *usually* a flat fee plus the extra fee for Greek, but as with everything YMMV.

and if not, then I'll pose it because I've often wondered about it.

Say a provider has a rate of $$$/hr, with $ extra for a trip to greece.

Now say you want to see her for two hours (Assume that her 2nd hour rate is the same as the first though it is often lower.)  

Now, does the paying of $ for the trip to greece entitle you to two trips to greece, or would that be $$?

It probably varies by the provider, but I wonder what other's experience has been.

Also, if you see a provider for an overnight, is the trip to greece tossed in as a bonus for booking so much time?

I didn't make my post clear after reading it over. I was trying to answer that question but didn't make it clear.

Usually if she charges $500 for two hours and $100 for Greek and you book two hours it $600 totaly fee. But YMMV as each woman sets her own rate, but that is how it is usually done.

It seems like over the course of 3 hours, some time in France and other realms would take up most of your itinerary.