Chief, your mistake is in looking for a justification for pricing outside of market forces. There simply is no objective way to set prices beyond "what the market will accept." A rational seller will always try to maximize the price he gets for his product or service, and a rational buyer will always try to minimize the price he or she pays. what a seller can ask is limited by competition - what other sellers of the same goods or close substitute goods are asking - and by demand - what buyers are willing to pay. Gucci and other Haute Designer's Handbags sell for $500, $600, even $1,000 -- are those prices justified, or are those Designers scamming their customers? I personally think one has to be more than a bit crazy to pay those prices for some Designer's goods. But some people obviously disagree, and as long as it's their money, why should I care? As noted in an earlier post, exchange rates are simply prices - the price in Dollars at which a willing buyer and a willing seller are willing to engage in a sale of Pesos. Exchange rates are not fixed by any authority; there are differences, albeit small, between the exchange rates set by different banks, bigger differences between rates set by banks and rates set by Cambios, and even bigger differences between the rates set by Cambios and Hotels and restaurants. And all of those differences reflect a lot of factors, like the costs involved in exchanging Dollars, the risks accepted that exchange rates will change, the ability to use Dollars without conversion to Pesos, etc. Mega might well give a better exchange rate because it buys inventory from American producers and has need of Dollars to pay those producers directly. But, at the end of the day, prices reflect "what the market will bear." If 85% or 90% or more American Tourists start paying taxis in Pesos, that would be a pretty good signal to taxi drivers that most of the market rejects the 10-1 exchange rate, and economics would predict either (a) taxi drivers would raise their exchange rate to 11-1 or 12-1 to attract more Dollars from American tourists, or (b) taxi-drivers who are completely indifferent to Dollars, or who would rather not deal with Dollars at all, would do nothing about exchange rates UNLESS they found that they were losing business to taxistas who were offering better exchange rates. As long as a taxi driver can stick with an exchange rate of 10-1 without any meaningful loss of fares, there is simply no incentive for him to change.
if you are trying to sell your house or a used car, are you going to try to maximize the price you get? Or are you going to make a subjective judgment of the "fair" value, and only ask for that? I suspect that most Americans, when posed that question, would respond that, of course they are going to try to maximize the price they get. Why should Cozumel taxi drivers be held to a different standard?