I love Glastonbury, but won't be trying for tickets this year, it is quite a significant rise admittedly, but Emily Eavis explains the reasons well, so it's not a surprise I guess.
Also, just to add, it's not a corporate festival, it's probably one of the least corporate festivals you could attend. There are 3 main charities that are supported each year, I think the closest thing you could argue is the drinks supplier, but there is no overt advertising.
To add, it's one of very few festivals that 'once you are in, you're in'. There are no arenas, you can come and go around the entire site, you can freely BYOB and consume anywhere.
Finally, what you see on the BBC is probably 5% (maybe less) of the entertainment and activities available. There are something like 100 stages with live music alone... not forgetting all the other activities; cinema, well being, circus, comedy, kids...
I did have a slight gasp at the increase, but it is still value for money. However I can foresee how people will question affordability given the financial pressures we're under. It's certainly too much for me.