Yeah it's a lot. Tool tickets are £100 for the worst seats in the arena. I like Tool, but I don't like them that much.
However, there are a lot of bands that are affordable tickets. I have seen bands that in indie circles are very highly regarded for £10 a ticket. I am seeing a German metal band called Ruins of Beverast for one of their very few UK shows ever for only £20, and this band is highly regarded.
Tricot, travelled all the way from Japan, are playing walking distance from my house, and it is £15.
The big names know they can charge a mint and get away with it, but there are still a lot of lesser known but equally impressive bands that will not do that.