Actually, for card and coin magicians, it would make an interesting coin stash.
It looks very easy to make, and who around here doesn't have a "dead" deck or two lying around? I have a black Arcane deck that I'm now starting to think of.
I also liked some of the how-to videos on the YouTubes about making a wallet out of old Bikes and some clear tape. I imagine such a wallet would wear out quickly, but hey, they're cheap and easy to make.
Equipment needed...
Glue - strong but thinly applied
Cards - close to but not actually perfectly squared (wanna make them look realistic)
Tools - I have a really nice 18v Ryobi plunge-cut saw as well as a multipurpose Dremel rotary tool.
Arcanes would be good for this - they're thicker and more durable, and that thickness will also provide a deeper stash compartment. Bike Masters would be good as well, and they're not so expensive.
Another idea - if your deck tuck box is beat to hell and the cards are worn, skip the box altogether and just rubber-band the two halves of the stash box together. Nobody would even think that an exposed deck of cards would conceal anything, would they? Let the outer cards and edges get beat up a little and a bit dirty, then most people wouldn't even want to touch them, never mind search through them.
Yet another idea - if you leave the top and bottom few cards unglued, you could spread them a bit to make the deck look totally legit to anyone observing. Cuts down on the stash space but adds to the concealment factor. It's like a book stash where the first chapter and last chapter are untouched, with flippable pages.