I agree the prices are getting too high - but the route from Isla to Cancun is 1/2 the distance than PDC to CZM - so naturally the prices are different
I fully understand the distance is greater than 2x. But the fare is 4.5X those in Isla Mujeres. I've always been mystified by business practices in Mexico. You will almost always make more with lower pricing and volume( ie Walmart) than you will be high pricing and pissed off customers. It's boderline criminal that a few power brokers are able to control something like this.
Sorry for ranting, but as a business owner I feel for all the folks trying to do business in Cozumel.
Keep the faith
Rich