One option is for the government to use its taxes to pay for inflation, especially for goods from outside the nation. There will have be some sort of "translation" layer of internal economy against that of foreign nations, so the government would have to develop tools and institutions for handling that. For the universal goods that the nation supplies to people, it can use taxes to buy the necessary supply chains. Companies that sell luxury goods will have to compete against the free articles, so there is pressure on corporations to adjust their pricing and quality against what the government offers.

For the URI (Universal Ranked Income), the bulk of taxes comes from corporations, since they are expected to regularly exceed the wealth caps by a good deal.

In any case, I don't think it is actually complicated, at least compared to our current economy. For example, prices of goods vary from one location to another, also known as cost-of-living. URI instead makes all locations in the nation have free basic goods and services, and jobs to have fixed incomes. People will be able to much more easily understand their fiscals, both as a business and as individuals. Much of our current economy is also built on exploitation, such as ghost jobs, the threat of firing people, wage theft, immigrant pay, and so on. By making it easy to understand how much money there should be, it makes it easier for people to detect and oppose corruption. Further, universal benefits like free shelter, healthcare, food, and so forth, allows for unionization since bad companies lose a great deal of exploitative pressure on workers.

What we lose by sacrificing capitalism's efficiency, we get back in controlling corruption and ensuring fair dealings.