Maybe I'm the odd one but I never saw the appeal of a meet & greet. If I had the chance to talk in depth for a longer time with my favorite musicians that would maybe interest me. But shake their hands, say hello and have a picture taken and then moving on? No, thanks. And I wouldn't be interested in such a thing, even if I didn't have to pay for it.
I felt the same way, initially. And my wife and I were steadfast against it. But we opened up a little bit on it if the price is reasonable. She did it for like $30 for Firewind on their last U.S. tour with Apollo as their singer. Then he left, but she got to see him and they spent a lot of time. We experimented doing it for Sevendust on their Bonfires tour a few years back. That was $50 per person. It was totally worth it. Good hang time, signing whatever, smiles all around, etc. We splurged on Alter Bridge on the Fortress tour. I think that was like 100 per person. However, while pricey, I felt what we got was worth it. We got in early, got to see a half-hour soundcheck, got special signed merch (a lithograph if I remember commemorating their anniversary and us as VIPs), and then we did the photo and meet and greet (which was a little rushed, but we got to ask questions and share some laughs).
That's probably the cap, money-wise, we'd ever spend, honestly. But if I see it for $50 or under for other bands, with good exposure and hang time, I'll pick it up, just to guarantee I get some pics with my favorite bands and some stuff signed for the walls. But if it goes above 50 or 60 bucks, it'd really depend on a lot factors for me to pull the trigger on it (who the band is, how much they tour, how much I like them, etc.)