Think i replied to that in the past but personally if i pay an extra, the extra is usually the tip for me. If she charge 200$ all included, then usually ill tip at least a 20, cause it does not go over my budget and im glad she was willing to go the extra mile. Now of course depend always if i had a good meeting. If no extra is allowed, then it would need to be a VERY exeptional session for me to tip.
Replies always varied for this, when i first started i wasn't tipping at all, it didn't crossed my mind, then some people said to me i should and all, so i started tipping but then i realized why should i tip for a "not so exeptional meeting"
The thing is i hate the concept of tip in the first place. In a bar you are literally expect to tip no matter the service you receive, and much more than 15% too. For a 4-5$ beer your expected to give 1$. In a restautant if you don't tip your usually seen as very greedy and they will notice you. Only fast food seem to be out of this ruling. Some of them like mcdo do not even allow tipping so when i go at other fast food i rarely tip. I mean ill give only the change that comes back, like if it cost 8.65 ill give the 35 cents... something like that. One case wich is a bugger me a lot is Subway... i live next to it, i go there very often, but i do not take vegetables in it or anything, im very basic. At first when i moved here i was tipping 1$ but then realized hell its costing me a lot... so i lowered it down to 50 cents... I feel i got to let a tip cause i go there often and they know me...
Anyway, back on SPs, it seem the norms are very separated. Some guys think because they book her lets say once per week that they should not tip, there repeated business is the tip if i can say. Other would think since they really like her and see her often, a tip should be given, while with a girl he will probably never meet again, then tipping would be a waste...
I dunno personally... guess it really depend on the budget...
As UncleBob mentioned, if you find an SP that still offer 180 and you have a good time, i would be more than happy to add the 20$ to make it 200. As 200 is more or less the minimum price these days. Its like when Wildtime started, i saw somebody there at something like 140$ or something, can't remmeber for sure but it was very low, i left a 35$ tip ... cause the price was so low.