Air, food, water, and education can be generated by homesteads easily exceeding quality of our present civilisation with minute investment beyond time. Shelter, pottery (by default lead and cadmium coated at present), and furniture can likewise be exceeded in quality, and from the streams or air a steady supply of mechanical force can be generated. Primitive metal works are created routinely in practice. Perhaps the force of a community might even be able to generate naive textiles, or surgical instruments from this.
It's true that with judicious planning a society might avoid much of the superfluous expenditure, and reduce upfront costs. Personal vehicles are done without by many, and so many trinkets seem to offer little advantage. Were this enough something new would have been born long ago. The drudgery of a life without the automaton holds us captive, and the requirements of the automaton are rarely met by those who escape.
I suppose then the question is what would it take to make something new and not only sufficient, but self-sufficient (to the extent to which this is possible, even US steel mills don't process ore)? Largely automated metal-works, textiles, state of the art circa-79 silicon foundry? How many hands, a hundred thousand? a million?