I believe the occasional entree tops $20.
But don't forget that Mythos is designed for the multi-course diner. An appetizer, entree, and dessert can easily push the pre-tax and tip bill over $30. Add wine and...well, you know.
The good news is that it's worth every penny and then some. And if you come from an expensive city like New York or London, you won't believe what a bargain the place is.