I was in bangkok in march,(going again in march for a month) going prices if you go to a beer bar the price is 2000 baht plus barfine of 500 Baht. You will have to pay the barfine in any establishment. that is for a short time which can last anywhere from 1 minute to 2 hours msog is usually out of the question you pop early oh well, but they do hang around long enough to give you a great massage. but it is so cheap that if you want somemore action and this is what i did a few times, you go out right at closing and pick up a free lancer or 2 for 1500 baht for an all nighter, that usually means once at night and maybe one in the morning, if your lucky.
The lady i spent some time with in bangkok, said to me after our 2nd "date" that i didnt have to pay her anymore whenever we got together.
Have a great time it is the adult disneyland of the world. So much debauchery. Dit