Here's an interesting thought for you, one that I've floated to another erstwhile deck designer before (Russell Common, a.k.a. sprouts1114). Sprouts has a concept for "Texas" playing cards - four suited jokers and each suit has extra cards in the court, a bishop and a cavalier.
He was insistent on doing his entire deck as a unique design, with value characters printed inside oversized pips in the indices. I suggested to him that he could make the deck for a lot less money IF he made it compatible with an existing popular design by using the same back - for example, a Bicycle Rider Back or a Bee Diamond Back. Bicycles, being the cheaper of the two, would be a good choice. Instead of making an entirely brand new deck, you only need to make the extra cards - though in this case you would also have to print with USPC to get matching stock, finish, overall quality, etc.
These could literally be "expansion packs" for the existing design. You could make a matching deck with four completely different suits in two new colors - blue bells and stars, green crowns and dots, etc. You could make a new set of suits that match the existing suits but in new colors - green spades, blue diamonds, yellow hearts, purple clubs, etc. You could make a set of cards that add new values to the existing deck - new courts, cards with values of 11, 12, 13, 14, etc., new jokers, etc. It would allow for the expansion of what we presently use into something new, yet would not necessitate the creation of a completely new deck - just the additional cards. One could even make "mix and match" sets - for example, sell the extra suits in small packs individually, or the extra value cards, allowing people to pick and choose the extra features they want to add to their decks.
This would be a highly viable and much simpler way to create such decks for the future.
