Well, there were a few different titles in Japan, and that box set has all of the singles as mini-CDs (3" CD) with both tracks on one side of course. When it was the only genuine singles package, the Japan Single Box was quite desirable, but now it's become more of a packaging-collectable.
If you’re a completist or just like the mini 3” singles, then get it. It’s very expensive now, the sound quality is not as good, and you have to play them 1 at a time. I’ve taken mine out of the box 2 times since it was released. Once to look at the covers, and once to rip them onto my computer, which was not really fun. I rarely ever listen to them now. The complete singles sounds better, and more convenient to me.
I’ve got that Japanese set and only ever opened the discs twice too, just to play some tracks and look at the lovely artwork. It’s a pain though to unwrap a single and take the disc out every time, just to play two tracks. I’m glad I got it though, it’s a nice collector’s piece. These days whenever I come across something that unusual, I buy two sets and keep one sealed. You never know what their value will be in years to come. I did that with the recent Queen ‘The Miracle’ Collector’s Box Set.
It's worth it if you want to have it as part of your collection. The lowest I've personally seen those boxes for is $100 to $250 CAD. $130 I was able to get on eBay three years ago on eBay from a seller in Quebec, Canada. At the time I thought it was crazy to spend $130 on it. Lol
Very hard to get. Last year I was able to get a couple of second hand sets that later resold. And snatched a brand new sealed condition for a ton of money. I will never open that one. Like to think of my collection as an investment.