WELP it only took many hours, many dollars, and several paper cuts, but here’s what I ended up with for stickers!!
I ended up making my own little accordion style folders, so each set of stickers is nicely sandwiched among the (surprisingly springy, yet snug) cardstock accordion.
Bonus: one phase of construction included GIANT PAPER SLINKIES
What a neat and attractive organization method! Makes it much easier to find and keep track of your inventory especially if you have many small flat things like stickers, bookmarks, postcards/prints etc.