I bought 10 Highcap preban G23 magazines from Glock, at a pistol shoot a few years ago. They must have been some kind of training mags. They are not like the current ones in the Glock annual were just the floor plate is bright orange. These are totally dayglow orange, except for the spring and are the latest drop free design.
I have never seen anyone with these before or since. I paid $25 each for them. How much do you guys think they are worth nowadays?

Yes, they were training magazines, I saw a few when I went through GLOCK armorer's school. They were molded in an orange polymer with the thought that the orange color would be more distinctive on the range. It allows instructors to visually see from a distance if the weapon has a magazine inserted or not and it discouraged officers from swapping range magazines for their duty ones. (Yes, they will try it from time to time, I don't know why.) Now we just mark our range magazines with the orange GLOCK floor plates and use them for malfunction drills where we (the instructors) set the magazines up with either dummy rounds or empty casings to jam the weapon. We prefer that our officers requalify with the same magazines they carry on the street.  It allows us to verify that the officer's issued weapon and his magazines function well as a system. Value? As a magazine, same as any other hi-cap. To a collector they may carry some premium. YMMV Good Luck!

They are produced by Glock for law enforcement use.  We use them as dedicated Simunitions magazines, in dedicated Simunitions Glocks.  They are sold only to LE by Glock, but anyone can buy them if you can locate them at a gunshow or something.  There is absolutely no difference between current production hicaps and the Glock training mags, other than the color of polymer that they are molded in.  The only ones that I've seen were still marked "Restricted", but I'm sure there are a few preban hicaps around.  I'd bet that you could turn an easy and fast profit on ebay with some.

They really don't demand a premium beyond any other pre-ban, there's plenty of them on the market.

I hear that Glock also sold these mags before the ban at GSSF matches