There's a way to share money in the new "Buried" zombies map for Black Ops 2. The method for doing so is the exact same as it is in the previously released map, Tranzit.
To do so, you'll have to first acquire the Galvaknuckles. To share money, you will need to go the bank. Right outside of the vault, there will be two keys sticking out where bank teller stall is. Punch the two keys with the Galvaknuckles to activate it.
Once you do so, you can share $1000 of what you're holding for the price of $100 and a money symbol will appear. Holding the button (square, X, or whatever controller you're using) will let you share more money at the same time with other players, who can then pick it up.
It's a bit more complicated than we'd like, but that's Zombies for you.