That's sort of my point. It is worth it to me. My intention was more to find out what other people's experiences have been with it rather than to start a philosophical discussion on whether it costs too much. Though it probably does in some objective sense.
I can't say about photo op experiences, because I've never paid for such. But I do have photos of myself with actors from before that horrible trend began. So I totally get wanting such.
If you have a particular favorite, or two or three? It could be worth it for that.
Without having been through that particular procedure though, I can tell you that the bigger a convention is, the more rushed, impersonal, and cattle-call like experience you're going to get.
I've been to small cons and big cons. And Vegas is a MEGA con. It's the grand-daddy big-time super-bowl convention.
Which means more than likely you'll be lucky to spend 15 seconds with the person, maybe 30 at the outset. Yes, you may get a hand-shake. A "nice to meet you" or something else. But you can sometimes get that from an autograph op too.
Really I don't know what to advise you to do other than this: go with your gut.