The prices of the tickets are set by the fans, so in turn, we are as responsible as Coldplay when it comes to the ticket prices. If Coldplay can sell out 20,000 seat venues on the day of sale with ticket prices of $95/$45 there's no way their management would allow them to lower prices, it just wouldn't make sense.
Trust me, I don't like paying $115 a ticket (after fees), but think about how hard it is to get tickets right now and then imagine how hard it would be if Coldplay cut their ticket prices in half. It's all about supply and demand. The actual market value of a lower level Coldplay ticket is a lot higher than what Coldplay is charging. Check stubhub!, ticketsnow, etc. and you will probably discover that people are buying and selling these tickets for almost twice as much as what they are being sold for on the general on-sale. So, as silly as it sounds, we should actually be thankful that prices aren't higher!
So in conclusion, I'm not saying that you guys shouldn't be peeved about how much tickets are being sold for, but I don't think your anger is geared at the correct people. We, as music fans, allowed the market for ticket prices to go sky high by continuing to pay these prices for tickets. If you want to make a statement, don't go. Do you think they'll continue sell tickets at such a price with half-empty arenas?