Price inflation is not an inherent result of debt-free currencies. Price-inflation-free currencies have already been devised. The issue is not whether or not but rather how real-time the smoothing of aggregate price oscillations are and can become with further advancements.
Money is no obstacle. A house, nation, or world is not rich or poor based upon how much gold or silver it has but rather how much vision, willingness, and actual cooperative work it does to proper ends by proper means.