This is ridiculous. Prices are not too high. If they were, the prices would go down. There is a limited supply of seats to the Book of Mormon. If those seats get filled every night at the exorbitant prices, then those prices are not too high. Furthermore, if people still want seats and can't get any even if they can pay the current price, then prices are too low.
If you're not willing to save up that much money to pay for the show, then you clearly don't value the show that much. There are people who do. Enough to fill the theater night after night.
I like your imperturbable perspicacity.