Musicians rely on concert takings these days as they don't get so much from record sales.
The costs go to all the staff, the technical equipment and the transport, so it's not as if the performers themselves are money-grabbing.
Mind you, when I hear that Barbra Streisand (whose concert tickets have eye-watering prices) has had a shopping mall built in her basement, I'm not sure this applies to everyone.
I once bought tickets for a joint concert with Elton John and Billy Joel. I thought that was a dream combination. It was in Munich, but I figured I'd cross that bridge when I got to it. The tickets cost me DM200 (before the Euro).
There was some speculation that they weren't getting on with each other, then Billy Joel dropped out, allegedly because he had flu.
I had seen Elton John on his own a couple of times, so I didn't go in the end. Never bothered getting the money back.