One of my bgs divides her customers into three catagories:
1) Veggies. These customers don't ask for VAS. $100/hr is standard tax for veggie and is quite welcome by most bgs. $50/hr is generally frowned upon by bgs, and repeat visits at this rate are tactfully discouraged. In the bg's point of view, a $50/hr customer is taking away opportunity for her to do a $100/hr customer. And if there isn't a $100/hr customer waiting, then the bg would rather be playing Mah Jong or Doh Di Zhu with her mates in the waiting room (as she can win more at the table than on the table, so to speak!). Worst are the wannabe repeat customers who only do repeat one-hour sessions at $50/hr and can't understand why the bg isn't friendly anymore.
2) Regular customers. These are loyal weekly, bi-weekly or monthly repeaters. Some lucky bgs have daily repeaters!! Understandably, bgs love these customers best. Expanded menu of services are available to loyal regulars; variable pricing, but, at a minimum, should be more than the $100/hr standard veggie rate.
3) 花心客. These are the guys that float from bg to bg, looking for the latest and greatest 神之手. Girls know most of these guys won't be loyal customers, so after a couple of persistant visits by this kind of customer the bg may lay a high price on the table. A $500 minimum tip for two sessions is typical. Interestingly, though, many of these customers decline to pay that! And even more interestingly, more than a few of these customers then jerk themselves off in front of the bg when the bg refuses to do it for them! In general, the girls don't mind when these customers don't come back.
Whatever kind of customer you are, in the end it's all about commerce. And, like in any business, loyal customers tend to get the best value for money.