The question of how an economy operated "pre-capitalism" implies that there was a change, over some period of time, to capitalism. Generally, when people think about such a change, they seem to be thinking of a change in economic organisation that caused the Industrial Revolution in England, with its massive growth in productivity and living standards. It does seem very logical that some such change was needed to spark the Industrial Revolution off, but decades of research, particularly into medieval England, involving painstaking archival work into sources like legal records and surviving account books, has failed to find it. To quote the economic historian Gregory Clark:

The more we learn about medieval England, the more careful and reflective the scholarship gets, the more prosaic does medieval economic life seem. The story of the medieval economy in some ways seems to be that there is no story.

Back in the bad old days, when the scholarship was less careful, the medieval economy was mysterious and exciting. Marxists, neo-Malthusians, Chayanovians, and other exotics debated vigorously their pet theories of a pre-capitalist economic world in a wild speculative romp. But little by little, as the archives have been systematically explored, and the hypotheses subject to more rigorous examination, medieval economic historians have been retreating from their exotic Eden back to a mundane world alarmingly like our own.

So, the way that the English economy functioned in the middle ages, in terms of things like taxes, prices and inflation, was in many ways like now. Obviously not identical: technology has changed drastically, and that has changed things like how government have raised money and built navies and so forth. Technology has also changed how inflation happens: in the middle ages when the government wanted to spend money without raising taxes or borrowing it would do things like debase the currency, with printing presses governments could print money, and now most currency is issued electronically. We also have independent statistics offices that measure inflation, and much better accounting by banks, data sources which were generally lacking in the middle ages. Similarly there are numerous changes in how effectively price regulations can be enforced and by who (though the widespread availability of illegal drugs indicates that there are still limits to government power). 

But, over all, big picture, the aggregate English economy in the middle ages worked similarly to now. Prices and markets were used to coordinate aggregate economic activity - to use a modern economists' view of the matter.

And it wasn't just England. Markets, prices, currency, and inflation appear throughout history and across Eurasia. I talked in the previous paragraph about modern economists' views of the matter, but medieval Islamic scholars discussed often discussed economic matters in ways very familar to modern economists. Ibn Khaldun of Tunis (1332-1406) analysed prices, profits and taxes. The Egyptian scholar Al-Maqrīzī (1364-1442) analysed an inflation process which hit Egypt in the period of the reign of the Mamluk, as part of his work as a historian, attributing it to the adoption of copper coins, which the Sultan Barquq had minted in large quantities (Figuera, 2018).

Going back even further, Ancient Rome and China had markets, currency, and concerns about inflation. For example there's evidence from before 242 BCE of the Qin state passing laws about the use of currency which were attempting to enforce their coins being used based on face value, rather than the weight (or value) of the metal in the coins.  Similarily there is numerous evidence of debasement of coins in Ancient Rome, leading to inflation.  (Scheidel, 2008). 

And it wasn't just Eurasia. Economic research into the pre-colonial African economies is only recently picking up, but there's some evidence of reasonably extensive markets and prices in Africa in the pre-colonial era on the Gold Coast (Shumway, 2017). 

This is not to say that all economies used prices and currency as an important form of economic organisation, there were other forms of organisation, for example the small population of St Kilda, Scotland, operated largely on a different basis as recently as the 1920s. 

Even looking at those places and times where we have evidence of markets, prices and inflation, there numerous cultural variations in the details of how those economies operated, both between places and in the same place over time. As there were in the 20th century.

In short, economic history is hard to make useful generalisations about.

Sources (not linked in text)

Stefano Figuera, Considerations on Islamic Economic Thought Regarding Monetary Matters in the Middle Ages, Œconomia, 8-1 | 2018, 1-28., https://journals.openedition.org/oeconomia/2928#quotation

Walter Scheidel, 2008, The Monetary Systems of the Han and Roman Empires, https://www.princeton.edu/~pswpc/pdfs/scheidel/020803.pdf

Shumway, Rebecca (2017), Review of Labour and Living Standards in Pre-Colonial West Africa: The Case of the Gold Coast, Klas Rönnbäck, https://eh.net/book_reviews/labour-and-living-standards-in-pre-colonial-west-africa-the-case-of-the-gold-coast/

Peter Temin, The Economy of the Early Roman Empire, The Journal of Economic Perspectives, Vol. 20, No. 1 (Winter, 2006), pp. 133-151, https://www.jstor.org/stable/30033637