To me it is not just about sex as how many time I would cum but more like a quality time I want to spend.
I always get my girls here in Texas for atleast 4-6 hours to make sure I can chat with them have some fun, spend some time in either club or bar or strip club and in meanwhile off-course sex and at the end of the night if the girls are good (I keep my regulars if I like there company) then it is all all worth it, Trust me when you have good time with girl and she is comfortable with you and having fun then she will go way more then what you have paid for and she can give you GFE and PSE.
I understand in Pakistan it is not like that but I would say if you are spending that much time and money then just don't have sex, have FUN, It seems like the girls here in TX are cheaper then the girls in Pakistan so if you are spending that much money then try to get most out of it, and again FUN is not just SEX, if it is then no need to spend more then an hours per day and you will end up spending less money and have more sex.
Just my openion