As the cost of production falls and demand increases, I'm fairly confident the cost of materials will rise, if we continue to live in a capitalist society that'

As the cost of production falls and demand increases, I'm fairly confident the cost of materials will rise, if we continue to live in a capitalist society that'll be the mechanism that controls the level of demand. The other option that could work is more material wealth in the commons, for example sharing the use of cars rather than owning one outright.