If Money is not a driving force for the federation, what would actually work to replace this....

[Arpy]

Striving to better oneself does not give you beachfront property, a yacht, a space shuttle, a ranch with horses or even a family winery
And if you want land on Vulcan ....forget it

You can keep your beachfront property if I can spend my life traveling the thousands of worlds in the Federation with little more than a communicator, a padd, and maybe a tricorder.