We considered going to see Pearl Jam in London in the summer, the ticket price?, £130 or so, shameless and shameful.
Price of tickets for bigger concerts has gone through the roof in the last 5 years.
Pretty much gone from 50-60 quid a ticket to easily north of 100 if it's a big gig (i.e. outside of an arena).
In my experience big indoor arena gigs (AO, O2 etc) are getting to the point were most tickets are 60+ quid.
The other issue nowadays are tickets for gigs are generally like gold dust. In addition, loads of tickets are tagged with some sort of hospitality angle or VIP moniker. Means a bigger proportion of tickets, and those left after initial scramble are massively over priced.
I suspect the other big driver is increasing cost. For venues. For shipping equipment. For staff etc..