I don't think Angus need be quite so pessimistic about extras at Artemis. Though caution should always be the watchword.
Agree everything beforehand, including whether the girl offers the service at all. This applies incidentally also to DFK and BBBJ. Unusually at Artemis, not all offer what is a virtual standard elsewhere. But of course many do. You will also find many girls offering CIM and COF at Artemis. You must ask.
The entrance is EUR 70, and the 30min standard session is EUR 60. That is correct. CIM is EUR 50 extra. Anal is negotiable, probably around EUR 100. Both the last are one off, i.e. not related to the time spent in the room.
But, if offered, DFK and BBBJ are in the standard price, as should also be COF, although I'm not 100% certain on the last.
So one 30 min session incl. CIM would be EUR 180, if you include the entrance price. Which as Angus points out, is a bit steep. So, EUR 110 to the girl.
But the whole point is that most don't go to an FKK for a half-hour shag and then leave. They hang around for hours, and if they've come over from the West Coast specially it'll probably be for 19 hours :-) :-)
If you do a longer session with CIM, say an hour, it would be EUR 170 to the girl. Already relatively cheaper. Do several sessions and the entrance factors in more cheaply as well. And you can have enough to eat and drink for all the time you're there at no extra cost (except alcohol), and enjoy all the other facilities too. So you have to look at an FKK differently from a brothel. You can't take the kids, but it can be a great day or night out at relatively reasonable cost.
So my advice to Merkur is firstly to RTFF (there are simply stacks of detailed reports), and secondly to decide what sort of experience you're looking for and how much time you want to employ, and then cost it. Both the high quality brothels you are looking at, and the FKK, are good options, where you should find the services you're looking for with no difficulty (unless perhaps a particular brothel has a house policy of no BBBJ - some do). More realistic that way.