As you'll be able to tell, I'm a long time lurker first time poster. (So I hope I didn't double post this.)
I have been living in Cancun since 1999 except for two 1 year stints in DF (2002) and Tijuana (2006).
I am not an expert on the P4P action because have not personally partaken however I have been to Plaza 21 many times and have worked in the Hotel Zone since 2003.
Due to my job I have taken quite a few people (all Canadian and American tourists) to Plaza 21. I can only tell that from my experiences that during the busy seasons (as of this week the overall hotel occupation is +80%) girls charge upwards of $200usd plus on-premise hotel fee of approx. $100usd for 1-2 hours.
There has always been a decent variety so probably a couple of chicas for every taste. Some young, barely legal looking spinners and some (IMO) way-past-their-prime silicone embellished M. I. (would never in a million years)L. F's. Also some Argentinian, Canadian and US girls.
Having said that, many girls are available for daytime and/or overnight service depending on your interaction with them at the bars and what you want to do with them, for example if you want GFE or just a quickie the next day/night. A lot of them are 100% hardened pros but there are still some unspoiled by the game. The unspoiled seemed to be the most receptive to future outside meetings. The last guy I took paid $250 for FS and hotel fee for 1 hour. He then negotiated for the girl to visit him for 5-6 hours at his hotel the next day for $100. He called me while she was with him because he wanted her to come back a different day for overnight. When I translated this to her she said she'd be happy to do it. When I asked for an estimate, she mulled it over for a minute and asked me, 'Would it be too much to ask for another $100? '. I actually repeated her words back to her because I couldn't believe she only wanted a c-note for TLN. She told me that he was nice and had already spent a lot on her between the bar and the hundred for the day visit and lunch at his hotel and a new bikini.
On another occasion, I took a couple and they forgot to hit the ATM before getting all the way there. After watching a few girls dance and their having had a couple of drinks, they wanted to buy some fichas for table dances with a credit card and the 'manager' said ok but they had to buy 10 fichas ($2000pesos) at a time. As soon as they paid for the fichas, this chica with awesome breasts but a pointy rat-like nose jumped off the couch she had been sitting on behind us and asked them if they wanted 'a private dance'. She must have impressed them because they spent all the fichas (5 songs at 2 fichas each) on private table dances and wanted to take her back to their hotel. We haggled for a while (I only got involved because the chica pretended not to speak English while negotiating) and she finally agreed on $350 (originally wanted $600 because there were 2 people to screw) plus $200 for bar fine. Since they didn't bring much cash they gave her $50 up front and paid the bar fine with their credit card. As I drove back to the hotel with the 3 of them in the back seat all I could think of was my leather seats getting splooged on since all I could hear was the chica slurping and the couple moaning. Turns out that this chica was the opposite of the previous girl. When I talked to the couple the next day, they told me that despite the hot and heavy in my car, when they got to the room the chica was all business. Wanted the balance of $350usd up front. When they reminded her that they already gave her $50 she threatened to walk out. Somehow they convinced her to stay and after the husband got his rocks off, once again the chica wanted to leave. But the wife hadn't gotten her O yet so there was still time on the meter. Again after some begging by the wife, the chica stayed till she finished her duties. And then asked for a tip and taxi money, complaining about how much she usually charges etc.
The first experience was June 2009 at the beginning of the highest season and the second September, which is as low a low season as there is.
If you stay in an all-inclusive hotel, expect to pay anywhere between $50 and $150usd to take a girl in. European plan hotels, such as Westin LagunaMar or Regina, Marriott J. W. Or Casa Magna (don't know where that one poster stayed in Marriott CasaGrande?), Hilton, or Fiesta Americana hotels should not charge unless it is extremely obvious that she's a working girl in which case they might not even allow you to bring her in. They'll show you some small print in the hotel rules about it being for the guests own safety.
My M. O. Taking tourists to the Plaza was very simple: they'd give me $40-$50usd (as many have posted, it's about a 30-55min ride depending on location of hotel) for R/T transportation from hotel-21-hotel. Taxis cost $40-$80usd so for some it was a bargain and for others a break-even proposition. No one I took ever paid a cover, which is often charged when arriving by taxi and actually goes directly to the taxi driver as well as their commission on the bar tab.
My only gain was at $25 between gas consumed and what I received and I got to look at the chicas. I never got a kickback from the bar or the girls. Never actually asked but I was informed by one of the 'doormen' who saw my local license plates and tourists getting out that I'd get the cover charge, so that was how I learned firsthand that it goes to the taxi driver.
As far as downtown Cancun goes, there are many 'massage' parlors and escorts available but as others have stated 'Adoos' ads without local number are complete scams. Also, as done everywhere many do bait and switch with photos. The same goes for ads in Por Esto 'newspaper'.
There are a few hook-up bars downtown with girls being really friendly and then making a deal for P4P action after guys have reached the point of no return. Some are pro's and some just want some cash. A lot cheaper than 21 but really have to weed thru some fuglies (sp?).
My personal opinion is that local (Yucatan and Quintana Roo) girls are not very attractive, but to each his own. Had a really good friend from the UK who lived here and found 'the most amazing woman on the planet' here. I almost hit him with a bat when I saw her. Love may be blind but lust is just plain stupid.
Fortunately, Cancun has been a mecca for people all over Mexico who (like me I'm sorry to say) heard the streets were paved with gold. So there are some real stunners from Guadalajara, Monterrey and Sonora which are known for good looking gals.
On the upside, Cancun despite recent rises in local crime, is still an extremely safe city to visit and live. The Hotel Zone especially is almost crime free, not counting hotel poolside and in-room robberies (leaving valuables out of the safety deposit boxes) and people paying off cops when they get caught urinating in public after stumbling out of a disco at 3am. And don't get me started with the local and federal traffic police on the highway leaving Cancun and the Playa del Carmen speed traps.
As for drugs, you'll get more offers at the Coral Negro market in the Hotel Zone than in Market 28 downtown. I really think that anyone who says the area around the ADO bus terminal downtown is a dangerous drug environ has gotten that impression from seeing the hippies and backpackers who stay in the hostels and small hotels near there rather than from any real evidence.
Been rambling long enough, so will close by saying that I'll be visiting Plaza 21 tomorrow (Friday 26th) night and maybe can give a more detailed/current account of the pickings.