Chief, you and I appear to be talking past each other. Just to be clear, there are two completely separate and distinct issues here.
FIRST, on the matter of Taxi rates which are set by municipal ordinance -- i.e., the Rate Sheet published by Christi listing permissible fares, in Pesos, for given taxi rides on Cozumel. On THAT issue, there is very clearly a matter of government- sanctioned monopoly pricing, a monopoly pricing with which I strongly disagree, but I can't do anything about it. And, as part of that issue, there is the not uncommon practice among some taxi-drivers of attempting to overcharge American tourists - charging 100 Pesos for a ride when the approved rate scale calls for a fare of 60 or 80 Pesos. That practice I think is clearly dishonest, unlawful, and inexcusable. I do NOT approve of or offer any justification for that kind of overcharging.
SECOND, there is the entirely separate and distinct issue of the Pesos for Dollars exchange rate offered by taxi drivers to tourists which desire to pay in Dollars rather than Pesos. I see this particular issue as a horse of a different color. There is no legal obligation for taxi drivers (or any other business on Cozumel for that matter) to accept Dollars rather than Pesos, and it would be ridiculous to claim that taxi drivers have any monopoly pricing power on exchange rates. If taxi drivers offer to exchange currencies at a 10-1 exchange rate, or an 8-1 exchange rate, or a 5-1 exchange rate, for that matter, no one is under any compulsion to accept the offer. Every rider has the choice - the choice to exchange Dollars for Pesos at another location, like a Bank, a Cambio, or a hotel, the choice to negotiate the exchange rate, or the choice to get out and look for a different taxi which might offer a better exchange rate. On the rate of the exchange rate ONLY, I am firmly on the side of the taxi drivers. There is a working free market in the exchange of Dollars for Pesos, and all Americans willing to make the effort to obtain the information can figure out what's best and act accordingly. Mike appears to disagree with me on the ground that many Americans will not know any better and will be "taken" by a 10-1 exchange rate. But there is a price to be paid for the freedom that a free market offers, and that price is responsibility. If any American, or even many Americans, are so oblivious to the fact that they are in a foreign country where the Peso is the official currency, or so unconcerned that they don't bother to ask about the exchange rate when they get into a cab, then it is not my place to provide them protection from their own carelessness. Caveat Emptor is the cost of freedom.