Cheap by European standards..
Jack,
Take one of the first class FKK clubs in Germany, for example Palace in Frankfurt: ? 50,- entrance fee, includes all drinks (non alc) and even a decent dinner buffet, plus ? 100 for an hour with a girl, or 2 half hours with 2 girls, total of ? 150 or U$S 195,- at todays pleasant (for us Europeans) exchange rate. Ok, it is a total different scene, but brought down to $ per pop, the same - in the very center of Europe. So, I certainly would not consider a Madaho's night "cheap".
For me, the very big difference always was, that in BA time not used to be a big issue. if the chemistry between a girl and myself was ok, she just stayed as long as she liked - and that was often quite a bit more than an hour.
It is of course the right of every business to define it's rules and to try to maximize it's profit. The market decides, if that works. Madaho's wants the chicas IN the club, making the guests buy drinks, for the reasons you stated below. And, as there are a lot of guests (mainly locals) who do not pull out girls, but who just drink, and chat with the girls, and buy them drinks, this might as well work. I just don't go there anymore - except, to have a drink myself, and maybe get some phone no's.
My last 2 centavos to that topic,
El Alemán