All I have to say about this is Bonnaroo is great - each year - I see on average 15-20 bands with 4-5 of those being BIG name bands that tickets for a concert would easily be $75-$100 each and I get to do this for less then $250 for the 4 days - seems like a bargain to me.
I counted it all up, and I saw about 25 acts during last year's Roo, almost all of them full sets. So, basically, an average of $10 per band. Where else can you get that value? Even the least popular bands I saw would still charge more than $10 a pop for one of their shows.