Agreed in principle. I think the initial slope should be a little lower but after about 30 years things should REALLY start to take off. So maybe $10 a year for the first 15 years and then double it every year thereafter.
If it's a flat fee for the first 15 or 30 years then it should take a lot of wind out of their sails.
If people start doing the math and saying "but at 60 years this is completely insane!" then just ask for a list of affected stakeholders that this would bankrupt. I suspect the only people on the list would be Disney.