Shatner visited my old home town about 8 to 10 years ago. There was a charge of such and such hundred dollars to dine with him and such and such hundred dollars to just be in the same line of motorcycles with him as he took a short ride beside the shore of the local lake. I didn't go because I wasn't going to spend that kind of money for something like that.
That being said, sure, he gets a certain percentage of the proceeds from his appearances, but a lot of the money goes to the ones who organize things and set everything up. It's not easy, there are a lot of logistics involved, permits of various kinds, etc.
I'm not saying that the man has never had ego issues, but sometimes in some of it there can be a false perception when there is a lot more at work than just someone's ego.