Wow a very nice display case! If only I had the ability to do this on my own. I can barely follow instructions 
but good work! It'll look amazing when full!
Haha, thank you very much! 
Yes, this would be pretty difficult to duplicate... do you think it would be worth it for me to figure out how to mass produce them and market them? I'd obviously need to find a lighter material, but I could even do multiple sizes (10 x 10 is pretty big, as you can see).
What do you people think, would you buy something like this? And if so, for how much?
If definitely want to buy one. But probably not a 10x10 one. I don't have a 100 decks I'd want to display if only because I wouldn't want to display the decks I regularly use or play with. I'd probably make good use of an 8x8 one though! If you were able to more cheaply mass produce a lighter case I would definitely be interested.
Would you leave it open like that or have some sort of cover? And price-wise, it would probably depend on the material and how much it costs you to make it right?
Mhm, I could potentially make everything fully customizable, from material, size, whether or not the customer wants some sort of cover, etc. But of course this is all theoretical at the moment... I don't know if it's possible for my dad and I to find an easier way to make these, lighter material, etc. And I don't even know if he's going to be keeping the CNC machine because we're moving soon 
I guess we'll see what happens, but I'll definitely talk to him!
Mike over at Brooke Michael's Poker World has displays somewhat like this in acrylic for $150 (clear) and $160 (black), capacity of 60 decks.
You could make these as an "on-demand" sort of thing. Yours is the proof of concept that the design itself is sound. Acrylic would lighten the load a bit, I think. You could also make the back less thick on the whole surface - create sort of a framework on the wood and carve out a fair amount of the rest to lighten the load while retaining a good deal of structural integrity. It's similar to the concept of a fold-open knife with a skeletal handle; weighs less but still strong. You also, as mentioned, have the option of using finer woods and even making these things more like furniture.
Another furniture concept - mount four panels in a box or rectangle shape on a Lazy Susan base, and make one of the panels mounted on hinges (either as one whole side swings to the left or right, or as two halves that swing open like kitchen cabinets). Inside, you could have drawers, shelves, whatever you wanted.
They need not be huge pieces of furniture with 100-capacity sides to them, either. You can make the sides as large or as small as your client desires. I feel that a furniture option is a good way to go because even a wealthy person only has so much useable wall space!
But yes, there's probably a market for this, particularly if you can keep the price reasonable.
Another idea: glass doors to cover the display. You can go with inexpensive cabinet-grade glass or for the precious deck collector you can go museum grade with UV filtering.
There's a lot of things you can do with the concept, as you can plainly see...
