Yes, of course! We are currently working on a design to showcase here
So you did the math and it made no sense? That's because you forgot the $5 shipping ;)
If you were to buy four decks separately, you would pay an extra $15 in shipping. This is simply a way to save.
These are Poker-sized cards. They are 3.5 inches high and 2.5 inches wide.
Don't see the answer to your question? Ask the project creator directly.