DW and I graduated same school/year. We had our 50th a couple of years ago. Entry was $50/couple and was held at "the Country Club." It's a nice but dated venue. The food was good. There was a cash bar, light entertainment, etc. All in all, it was a good time and I'm glad I went.
During the meal, DW (who has "silver" hair) said "There's a bunch of old people here!" I had to laugh at her semi-serious comment.
Since I lived many of my years in the town where I attended HS, I often ran into old class mates - even w*rked with a few. Our graduation class was over 500 (would have been more, but at the previous X-mas, there was a mass exodus of girls who would not have made it to graduation without "showing" - which was verboten back in the day. How times have changed.) With that many graduates, we've lost a bunch of people. I think I calculated it was 14% at the time. Also, with that many folks, there were plenty of folks I didn't really know when I was in HS. Just as a guess, I'd say we had about a 35% showing of the class - difficult to tell with spouses, many of whom were class mates like my DW.
Back in the day, we all had our various "circles" (cliques, in some cases). There were the jocks, the cheerleader/popular (aka rich) girls, the nerds (my circle), the "hoods", the "strange", etc. I noticed that some of the cliques still existed after 50 years. It was clear that many of these folks not only never moved away, but they had stayed in close contact with their circle. There was a fair amount of "intermarrying" among the "popular" students - most were still together, which sort of surprised me.
I'm sure there were a number of fairly well-to-do folks there, but I was not aware of their situations beyond knowing that this one was a lawyer at a local firm or that one was a professor at the "local" college, etc. There really were no "recognized" stand outs (no rock stars, no "celebrities", etc.) We did have one guy who became an under-ambassador to a European country.
I suppose it was kind of "what you would expect." Lots of weight gain, lots of bald heads, lots of "silver" hair, etc. But, there was one "girl" who had been one of the more popular girls back in the day. She was there with (IIRC) here 3rd husband who appeared to be 10 years younger. But she looked at least 10 years younger than he! She apparently had some "work" done - at a good clinic. During HS, she had acne and now, apparently had received a good "resurfacing" job, probably a tummy tuck, "augmentation", lips, lift and hair color - not to mention fabulous make-up. She was in such contrast to virtually everyone else that she made a stir wherever she roamed in the hall. I didn't know whether to feel "good" for her or to pity her. I suddenly felt myself back in HS for a minute or two. That quickly passed and DW and I spent a very pleasant evening with my best HS buddy (he was best man at our wedding) and his mail-order bride from RP.
Two years later I continue to receive the occasional "Sad News" email from our class "historian" who keeps track of those who "graduate" to another dimension. If there is a 55th, I'm not sure I will go, but I would strongly consider the 60th, if DW and I are still up to it.
HS was not a bad time for me nor was it nearly a "high point" either. As time passes, the bad memories fade and the good memories remain. I think that's the way it should be. YMMV