> The much simpler way to avoid squatting is to make .com domains cost $200 a year

A monopolist hiking prices to this extent will likely see legal action against them. That's a 20x increase you're proposing.

It's also unlikely to have a material effect. .com used to cost $75 a year back in the day, and that didn't stop squatters, and high value domain transfer sales. $75 in 1990s dollars is about $150-$190 today.