It's supply and demand. In the past tickets were much cheaper but they were hoovered up by bots and re-sold for £200 on ticket selling websites so you could argue that the price was way too low and the excess demand was seeing money going to touts instead of the artists. Of course, when I say touts I mostly mean the ticket selling websites themselves like Ticketmaster because they owned those re-selling sites.
I know I'm never going to pay those prices so I have resigned myself to the fact that I probably won't see many big bands playing anymore unless I decide to go to a festival. I just don't see the value.
That being said. I'm finding it difficult to find the value in anything these days. Everything has gone very expensive. There aren't many budget options anymore. Football is £30 a ticket, cinema is £12-£15, McDonalds is nearly £10 for a meal, a pint is £6 even in poor areas, a bog standard local restaurant will be £15-£20 for a main, a ticket for the golf at the weekend was £100, the local soft play is £15 for an hour for the kids, a night in a travelodge is £100, a train ticket to London can be £300, a 2nd hand car will be £20k for anything half decent and that's before we get to the cost of housing. Seems like if you want to do any activity these days you have to be fairly comfortable financially.