My assumption about this was that each generation has only one Midnight Blue, but they are so hard to find that people forget what they do in between. I thought the author was making the suggestion that the Midnight Blue was basically the equalizer. I could posit the political suggestions involved there, but I'm trying not to be a broken record.
I think you're probably right on that, but I get the impression that this is only the 2nd iteration of the spheres, so we'd have to wait until the next Midnight Blues were found to be sure.
But, I would like to know why this world was stuck in the 70's; Partridge Family, sphere catelogues instead of databases, cashier's cheque instead of automatic money transfer, etc. I don't know why, but it kind of struck me as odd and needing some explanation. Maybe people stopped creating new art and developing new technology because their efforts were side-tracked by the quest for "powers"? Just a thought....
I think it was just plain set in the 70s, though of course a 70s with the spheres added in, an alt-hist fantasy I guess you could call it. Since Johnny Carson is the popular talk show host, assuming that's similar to our timeline, he retired in 1992 and died in 2005, so that gives a couple decade window for it to happen. Unless Carson had some longevity spheres or something.
Anyway, cute story. I liked the kid and I was rooting for him. His dilemma was very well set up. That would be a hell of a hard choice, deciding whether to sell that or not. It was actually a little disappointing that the millionaire had so handily cornered the situation and could tell him straight out that the boy will never get the staff and other sphere. That made the decision a no-brainer. Would you rather have $850k, or a shiny sphere that does nothing for you? If it hadn't been that cleancut the dilemma would've been that much stronger I think. but still, I generally liked it.
One thing that I didn't like so much was that the whole "collect the spheres" idea reminded me of video game sidequests that I tend to avoid if possible, of the "collect 100s of collectible items to get something worthwhile" variety. Especially Diablo 2, wherein you have a combiner that takes lesser items and makes a greater item. As a result, to really make it ahead in the game you collect several cracked gems and combine into a flawed gem, find several flawed gems and combine into a better quality gem, etc... A few minutes into that and I was annoyed at the amount of time it was going to take to get any worthwhile gem (which can then be permanently implanted into an item to give it extra attributes).
--Anyway, that association isn't really a flaw in the story, just a flaw in the video games it reminds me of.