As Batman mentioned, you haven’t specified the location. But from what’s mentioned I would assume you are asking about Bangkok. We read recently about BF increase in one of NEP (Nana Plaza) establishments presumably Cascade. The increase in barfine was from ฿600 to ฿700.
Many predict other establishments in NEP will follow soon, who knows what could happen, they could outsmart us all and increase it to ฿800 or stay at the current rate, can't tell. But back to your question there is no magic number on how much you need to pay a girl for her time it depends on few things such as your age, looks, do you sound like a newbie, chemistry, etc. But in general here is the breakdown for Bangkok prices:
Barfine: ฿500-฿600 most establishments nowadays are ฿600 (you Cannot negotiate this, it’s set the same for everybody you and me) Note: some alcos on the street near Nana has a BF of ฿300.
Lady drink: ฿120-฿180 depends on the establishment bar or GoGo, drink type. (same as above)
Your drink: ฿90-฿180 depends on the establishment bar or GoGo, drink type (same as above)
As for what you pay the girl for her time regardless ST or LT, you can negotiate this to some degree, just don’t overdo it, or it will affect your experience. Prices in Bangkok generally speaking are:
ST: ฿1500-฿2000 (The max I paid is ฿1,500 I would never pay 2000 for ST, but you will get this once in a while were the girl will refuse anything less than ฿2000, I decline in such cases)
LT: ฿2000-฿3000 ( you have to ask people who do LT I’m not a fan, I do ST and cut em loose, but from what I read in Bangkok people pay on average ฿2,500 until morning the next day)
Freelancers ฿700-฿1000 girls you find on the street - just be careful who you pick.
Some will argue that they got ST in NEP at ฿1,000 it could be true for some guys if they know the girls well, or they are regulars or have special thing going, Probably you can get this price at Alcos on the street such as Check In Bar, but generally speaking for the general population and fixed bars that’s the break down. Barfine prices in NEP haven’t changed in years, this news about ฿100 increase is recent, I was there last Oct and the price was still ฿600. So Dec is new news.
I'll include Pattaya prices just incase you want to ditch Bangkok obscene prices:
ST: ฿700-฿1000 (though in massage parlors and other low profile venues in Soi6 you could get ST for ฿500 + ฿300 BF)
LT: ฿1,500-฿2,000
Freelancers: ฿500-฿700ST & ฿700-฿1000LT - just be careful who you pick.
Good hunting.