Man, of all the places in Asia you pick the priciest by far.  Consult with any taxi driver upon arrival.  As in most overseas places the cabbies have all the info.  In 1994 it was $200 for a quickie with a fairly goodlooking girl.  Not like Thailand or other places where you could spend  a week with a pretty girl for that much.  I'll bet it's even pricier now.  

Check worldsexguide.com