Rates at premier have been quite standard for a long time now:
Door fee for 40 minute session = 150 (includes all "within-the-limits" service including bodyslide and happy ending, and usually LFK/DFK)
"Extras" in room rates are standard 50 BBJ, 100 CFS. Anything over is upselling. There are and have been girls who will try to overcharge; many have been discussed in this forum. Remember not all the girls do engage in all extras, but generally yes. TBH some of the better sessions I have had have been with girls who stay within the limits and have learned how to put that little "extra" bit of sensuality in to compensate. TETO & YMMV
Tipping as discussed here is above and beyond the above door fee and extras rates, and is 100% discretionary. If you had a particularly good session then its up to you. There are those here who advocate tipping on top of standard rates, and those who advocate against in an effort to keep a lid on what could easily lead to price gouging. I suppose one could gauge tip levels as similar to in the service sector anything from 10 to 20% on top of bill. I would say only tip the MPA based on the rate for extra received. 20% on 50 BBJ means 10 more, etc.
So bottom line: if going to premier with FS in mind, then you need at least 250 for entry and "entry". Tipping more is up to you. Be sure to establish good rapport with the girl from the outset and clarify what you want when the moment to discuss comes.