Just about your last sentence, “the market will overcome price controls”- yes but at what cost? Honest people might die or starve in the process, criminals with machine guns will take over the black markets. People might resort to eating grass and insects if there are food shortages.There might even be wars instigated by the state to force you to abide, like what happened in the American Civil War.
Well exactly how trading will be done under hyperinflation is anybody’s guess. The market will find thousands of ways to trade depending on the circumstances.
There is not an accurate way to determine what the inflation rate is going to be by the time you show up at the shop to buy something. You might recognise a trend of prices doubling every day so you anticipate that your $50 bag of flour might be $100 by the time you buy it tomorrow. But if you get there and there is only one bag of flour left and your neighbor offers $120 for it and you only offer $100 then the inflation on that product went up immediately.
You find the “current” market price by going to the store and making an offer and seeing if it gets accepted. It will be like an ongoing auction that gets more crazy as the shelves get more empty of product.
Of course this is only an illusion. The flour did not become any more valuable than it was yesterday, only the money became worth less. It still takes you 6 hours of work to earn enough money to buy one bag of flour. You might just ask to be paid in a currency other than the official fiat money.
Nobody can actually calculate the overall inflation rate at the time very accurately, only after the fact. And the official inflation rate as calculated by the government is a lie. And the official inflation rate for the country is a useless number for the consumer because it will vary from product to product depending on its demand and supply. It gets adjusted every second by what a buyer is willing to pay and what a seller is willing to sell for, for each item.
Even now, you will hear “the official inflation rate in the USA is X% - not counting food and gas” what use is that number, we all eat and drive. Its like saying the official price of a new car is $4000 , before you add the engine and the tires. Yet if you go to the store you know that a year ago we paid $4 per pound for steak and now you pay between $10 or $12. There is no official inflation rate that reflects that, but you just know you have to pay twice as much if you want the product.
Individuals quickly learn that if they buy food or other essentials every day, it goes up. So they take every penny they can to buy all the essentials they will need and hoard for as long as they can. Amongst private individuals who cannot calculate the lost value of the currency, they will likely trade amongst each other with valuables.Nobody will use the state currency to pay each other. The state will likely ration and control certain things and insist you use their money to buy it, but amongst people they will use the products to barter. Food, gas, clothing, cigarettes and of course gold and silver will be used as barter. Whatever you have that is more valuable to someone else will become the currency for you to buy whatever they have that they value less than your offer.
Internationally it is hard to say. If a currency is debased as bad as Weimar Germany nobody will accept that currency for international trade. They will have to buy another currency or gold or silver to trade with. The only difference nowadays as you noted is that ALL countries are debasing their currencies. So even though the dollar is worth less now to the consumer, so is the Yen and the Euro. So maybe governments will keep trading with each other in their own currencies.
Individual international businessmen will trade with whatever works in the situation. The American businessman migh ship raw material to China in exchange for finished product that he can ship back. There will be bartering just on an international scale. Businessmen who know each other and know that their counterpart has valuables backing his credit will accept each other’s IOU’s.Official banks will become irrelevant and blackmarket barterers will evolve.I deposit 1 ton of grain that you give to a baker who deposits 500 breads which my neighbor delivers to hungry Italians for Italian shoes. We agree amongst each other what the relative value of each of our products are.
Who knows what guns or drugs or food or building materials will take the place of currency. The scarcer the product you want to buy, the more shady will be the competition bidding against you. Weapons grade uranium, pharmaceutical cocaine, stolen military computers, who knows what will be used in the underworld.
Smart businessmen will deposit their savings in hard assets that will still have value after the state and its currency collapses, like real estate or ships or heavy equipment or factories or farms.
Why do you think Germany is asking for their American credit to be paid in gold, and China and Russia are buying up gold by the megatons?