Here's a place about 2 kilometers out of town on the coastal road towards Huatulco: "Tony's", on the right hand side of the road. The usual dancer/strip show (starts at 10 pm, though the chicas are on the premises from about 9pm), modest cover charge at most (I paid none, perhaps because I got there before the show started), and there are about a dozen chicas (6s and 7s mostly). To go to a back room for a one-shot deal, 30 min. affair, you'll pay 600-800 pesos (starting price offered me was 1,000, ended up paying 600).

i would have been there about same time as you last year and went to that same place.
i think it was shit.. smelt of puke and girls were more like 3s and 4s. i dont recommend puerto for mongering but an excelent place to take your girl for a beach holiday and relaxation. i recomend lisa's bar for cool cocktails on the beach...