Dances vs drinks vs hotel
Never done a dance here, but from what I've heard they are overpriced compared to taking the same girl to the hotel. 3 dances will cost you the same as her price for going next door, excluding the bathrobe tip, hotel room, and cum boy tip.
What I do think is worth while, especially with a girl you don't know, is buying her a drink. For $8 you get to test drive the girl before you go arriba. You get to inspect her with your hands (maybe more) to see if she's had any body work, needs any body work. You get to see how she drives / what she allows you to do. You get to see how she accelerates (how fast she drinks her drink) giving you an idea if she will rush you once upstairs.
You should never buy a used car w / o taking it for a test drive and having your mechanic check it out. This does cost a few extra pesos, but well worth it if it keeps you from buying a lemon. No different than buying a used chica in Tijuana.