Yeah I really wish there was a way that I did not have to pay that much money for beers. I have done it before but only here and there because that adds up really fast.
I've said it before and I'll say it again; smuggle beer in.
Take the coldest beers you have, wrap a few in a blanket, throw a few in random pockets in your bag and get guys in your group to tape mickeys (pints, flasks, whatever you want to call them) to the inside if their leg. My group normally has about a 50-75% success with beer and 100% with the liquor taped to the leg method.
Worst case they find some of the beers and take them. Totally worth the risk when the price of beer goes up about 10x inside the festival.
I have never heard of anyone getting any sort of trouble for trying to sneak beers in, so you mid as well give it a shot. (though I assume no responsibility if they change their chune this year and try to kick you out)