My parents took me to see the Oak Ridge Boys when I was 11. It was a big family outing with aunts, uncles, and cousins included. I did not go to my first concert with friends until I was 16, and it was a BIG deal that me or any of my friends got to go. When I was 22, I took my 13 year old sister to see NKOTB, twice. The second time even "camping out" for tickets with a friend of mine, she took her cousin (though we did not take the girls to the "camp out").
My husband and I took our son to see Jimmy Buffett when he was 5 years old. We are big Buffett fans, and he still talks about going to this day. But, I have to add, we take our son to all sorts of things like that. We went to see King Tut in Dallas when he was 6. He's been going to Monster Truck Jams since he was about 2 (yes with ear covers). Just because it costs money doesn't mean he won't appreciate going and look back fondly on it when he's older.
My sister and a couple of her friends took their daughters to see Taylor Swift a couple of years back when the girls were 5/6 years old. They made a whole overnight of it. The girls had a blast before, during, and after. They still talk about going.
I personally think it's important to give children these types of outings even if they are young. It's an experience they can take with them for life.
Why would you take them to see Diego, Dora, and Sesame Street Live, but not what they are interested in now? They get the experience of going to such things and you get the experience of seeing them experience it. It's all part of making them the person they'll grow up to be. If you never take them places, they won't know how to act/respond when they do do them when they are older.