There are many reasons for the price explosion, but a critical factor has been the ability of businesses to write off tickets as entertainment expenses -- essentially a huge, and wholly unnecessary, government subsidy.
These deductions have led to higher ticket prices in two ways. On the demand side, they have fueled competition for scarce seats, with business taxpayers bidding in part with dollars they save through the deductions. On the supply side, the large number of businesses bidding for expensive seats has driven the expansion of luxury skyboxes and a reduction in overall seats in new ballparks.
I sat in a luxury box for a baseball game once. It was interesting in both good and bad ways. I don’t begrudge their existence. But I never once felt like it was something the government should be subsidizing.