Wizkids Rules!

Cargo hold reads “Add 2 Upgrade slots ([CREW]) to your Upgrade Bar. These Upgrades cannot have a cost greater than 4 SP. This Upgrade may only be purchased for a Ferengi ship and no ship may be equipped with more than 1 "Cargo Hold" Upgrade.”

Does this mean each card in the cargo hold cannot be individually greater than 4 points or that both cards combined cannot exceed 4 points total?

The combined cost of the two upgrades cannot exceed 4. This is similar to the upgrade cost restrictions of Cryogenic Stasis.