Well, TB, the decal thing happens almost exactly the same way as the kit stash thing.
If you want to build over 200 units in model form,,,,,you are going to wind up buying decal sheets that only have 1 or 2 schemes that you want, but have 5 subjects on them. You wind up with a lot of unused multiple copies of kit decals, and "half-sheets" of aftermarket decals. (or more than half)
I know that the current wisdom is to not have a stash, and to buy kits and decals as you need them for a project,,,,,,,,,but, the people that believe that, won't be anywhere to be found when I want to do the VA-156 F11F-1 Tiger, and the kit turns out to be OOP, and the decal sheet is OOP and hasn't been listed for sale since 1988. So, I have them in stock now, ready for the day I want to do them.
Rex
(in short,,,,,,I did this on purpose, the kits, the decals, the paints, and the books)