The price of beer (and indeed anything) at such events (sport, music etc) is extortionate. I have smuggled beer into grounds in the past myself. Often, I can just refrain for a few hours - you can buy alcohol but you can't take it on to the terraces so you need to drink it before you take your place in the stadium. That limits consumption really.

Which dark beers do you like? Never been to a US Football game, probably should have done when I lived there.