You may not appreciate my previous statement, but consider the big picture. Almost everyone who works in Mexico is unionized or has their business behavior controlled by a "trade association" as well as by the government. On the outside, it looks like a free market even though it isn't. In the case of transportation, the van drivers are allotted a little piece, the bus drivers get somethine, and the taxis have everything else.
The Taxistas --the guys who drive the white cabs -- are the most politically powerful union on the island. They endorse political candidates and policies, spend freely for those campaigns, march and picket and strike for what they want, and deliver the votes. They are the reason that we have so little public transportation on Cozumel. There are no gypsy cabs or private dollar vans here -- those that have tried had their thinking quickly and effectively corrected. Because of their influence, it costs much, much more to taxi to a hotel, to certain condos, to the cruise piers, to the caleta, to Puerto Abrigo, to the Money Bar and a lot of other places than to be dropped off at an abarottes or home a block from any of these locations. They still exchange dollars at 10 to 1, they lie to gringos (locals and visitors) about tariffs, and often will not produce change to the tune of 20 or 30 pesos.
At the end of the day, though, all this is information that you probably don't want to know. So, I'll finish with the statement that you're quite free to make your own informed decisions.