Perhaps just like the Hobbits used the calendar set up in Gondor by the king (i.e. King's reckoning) they used some sort of "universal" currency also set up by the kings and/ or stewards? Perhaps this currency was used among most settlements of Hobbits and men. Though I doubut that elves or dwarves used such currency, as stand-offish as they can be.
Wealthy families like Bagginses and Tooks I'm sure had a system like the old days of the humans. The weathy people owned scads of land and had other people work it for them. The landlords in turn got a percentage of whatever money the peasants made or grew. They also may have collected rent from people living on their land. For all we know, the Gamgees of Bagshot Row may have been paying rent to the Bagginses!!