Yes I believe things have changed. Copied from a post Lan Sluder made about two weeks ago...
"The US$50 fee is the renewal fee (per month) if visitors want to extend their tourist card after 30 days.
Exit tax by international air is US$35 or US$18.75 by land. By water you just pay the conservation fee US$3.75. Air exit taxes are now included in most international air tickets so tourists don't really squeal about the pinch, since there are so many air fees and taxes, especially from the U.S."
In other words, you will need an extra $50 if you stay over a month and probably nothing extra if you leave by air (should be included in your ticket price).