Here is a brief walkthrough of the idea:

Every community shall be organised by a council featuring twelve separate departments, namely Environmental Issues, Education, Sport, Art, Health, Construction, Transport, Agriculture, Public Safety, Public Satisfaction, Technology and Research.

Each department shall contain a workforce built around volunteers. These volunteers will contribute to the department through providing their energy. Eventually the stronger characters will be noticed and elected into the position of supervisor. These supervisors will manage the trade of the department, and ensure that all materials required are acquired. They will also ensure that the workers are given all essential materials required for a comfortable life. They may be cast out of office and replaced by younger/stronger individuals via debate and election.

Each department shall consist of a house from which plans are drawn and meetings are conducted. This house is to be open to all workers of the department.
I foresee agriculture as becoming the largest department within every council as demand for food will always remain higher than other demands, followed by construction.

Rather than shopping for materials therefore, all materials will be traded between departments and shared amongst the workers, with pricing of goods in terms of amount of trade based around Adam Smith's principles of Supply and Demand.

International trade will be organised by an international body of twelve departments based eventually in India, which shall monitor the growth of the world and supervise trade, with the support of seven bodies consisting of the 24 largest departments of each of seven continents, which have the added responsibility of collecting information on supply/demand requirements across the continent.