Based on the observations among animals the presumable to not have much ability for abstract though, such as birds, I would say that, yes, some form of 'account balance' exists in the brain. One example supporting this is the 8 years old Gabi Mann of England, who regularly gives the gift of food to her local crows, and they in turn bring back to her beads, buttons, nuts and bolts, paperclips, earrings and other goodies that, amazingly, the crows recognize as rare finds, and, even more amazingly, associate that rarity with value.

This ability has lead some clever entrepreneurs to train crows to steal coins and even paper money, sometime right out of the hands of their victim, in exchange for tasty treats back home.

So, I agree that the concept of "balance" existed before money. Money just made that idea easier to manage, and control.