TG-16s are in CD jewel cases, so to make them match "boxes" you'd want one like that.
The DS case dimensions are close enough to jewel cases. Exact height, about 3/8" shallower, and about 150% the thickness of a jewel case.
Plus, I'm not talking about something made exclusively for the TG-16. It would be really easy to add a couple of extra tabs to hold them in place along with whatever tabs are needed for the GG. Sort of like a mini UGC for oddball portable and tiny, credit card-sized games.
Honestly, I agree with you all about the combo set-up, I love the idea of making a few dozen types of cases for each of these game carts and have them very well made for there one/two/three intended cart type. (Like the GB/GBC/GBA cart case) I haven't asked for a quote yet on this GG style mould yet, but I'm guessing it will be around $10k-ish for the mould. So I'll have to sell something around 15k-20k pieces to break even.
Again, I don't mind breaking even and then having these available for anyone who wants to attain them, my main concern is how long it will take to move say 20k pieces. (Also, once I have the other case up and running and it's mould paid off I can use it's profits and help payoff this mould)
So, what I have to do it look at all the moulds I want to make, deem what ones will move the fastest, then with those moulds product's profits swing back around and scoop up the lower quantity cases. (Like the Virtual Boy)
Thoughts?
Honestly, this project isn't going to be profitable, ever. I think your money would be WAY better spent on something like a better UGC design. The market for this sort of product is already niche, and GG-specific cases are way beyond niche. TCP is a great place for feedback on what a case should and shouldn't include, since we're all so familiar with casing our games, but our interest in such a specific product is by no means indicative of the overall market. A UGC that more snugly holds games and comes in different colors would probably be a very welcome thing. Hell, just offering what already exists in different colors would probably end up selling like hot cakes and I'm willing to bet that you could very easily wholesale a TON and make your tooling money back before they even reach the consumer.