I'm going to throw a few random points out there and see what sticks.
Energy is the bottle neck on quality of life in EP. Even if you can recycle all the matter in a habitat however you want to turning refuse and waste into more food via fully automated processes takes energy. Orbital solar cells generates a lot of power, but breaking things down (sub-)molecularly takes a lot power as well. The computational power available in EP is also staggering. Even assuming that the watt cost of a calculation improves by 100s or 1000s of times that is also a very high cost. All the quantum tech would be a huge drain. Moving mass across the system is an epic drain. Etc. Given that energy will still be a serious, maybe the only, limiter on what people can actually do. So I could imagine energy being used as a "gold standard". I could see it even being used as the anarchism-corporate currency.