Not much. You need to look at this from economic perspective. What you see right now is the result of panic in the market.
Consider USD as a good next to rest of the goods like milk, sugar, bread and etc. Now imagine government announces we are going to ban the sale of sugar in three months. What will happen is that two groups of people will rush to buy sugar beyond their actual need: 1 - The group that need sugar for their business or daily consumption. 2 - Group that actually doesn't need sugar but knows the price of the sugar will go up and likes to make a benefit and "ride the wave"
This panic will result in a demand much larger than society's actual demand and will spiral the price of sugar up and with it any other goods that depend on sugar like cookies, chocolate and etc. However, it can only go up to the point that the actual users of the sugar would be willing to buy it. So it will eventually stop at some point either before or after the 3 month deadline.
Now when the ban on sales of sugar is implemented and hopefully it is effective enough to completely stop the supply of sugar, then the only source of sugar will be the inventory of those groups that bought it like crazy. meaning sugar becomes scarcer and scarcer in the society. However, the price has already reached the point of saturation and nobody can afford to pay any higher for it. At the same time another thing will happen: people will start to change their behaviour (use no sugar) or find alternative sweeteners (like Date's extract) which will drive the demand down. At some point the price of sugar in black market will stabilize due to diminishing supply and demand. And it may even get to a point that the alternative sweeteners totally replace sugar and the life will continue.
Hyper inflation will only happen if: 1- You supply the society with more and more money to buy more expensive sugar and 2- There is sugar to buy.
This scenario will happen to any non-essential good. I agree USD is a much more important good with a much more far reaching effect on the market but the fact is it can be replaced or in other words it is non-essential. We need USD to buy things we need from international market. The government will still supply the local market with essential goods like wheat, meat and etc through barter or alternative currency agreements. Luxury products will no longer be imported and yes, people will no longer be able to do recreational trips to Europe and elsewhere. But life will go on.
Many of you are probably too young to have seen the war era. Back then, the USD started to spiral out of control from 7 Tomans to 70 Tomans and then higher in the black market. However, it stabilized at some point as people changed their behaviour and supply and demand balanced themselves. Western and luxury goods were rarity and almost everything were built domestically, travel abroad was a very rare thing and people spent their holidays together with their families or in other Iranian cities. Not everybody had a car which helped the air stay clean. Government supplied industries with their internationally sourced raw material either through subsidized Dollar or directly. I lived through it and it was not bad at all. Families were closer and local industries were stronger. Overall it was a healthier and simpler life in my opinion and I don't recall people dying out of hunger.
Right now Iran is in a much better position compared to the war era: We have lots of educated people who can run our industries and production in the absence of international competition. We have a much larger economy and country is much more wealthier compared to then and we have a world that is sympathetic towards us and is willing to help as far as it can.
Iran should grab this opportunity and get rid of reliance on USD once and for all.
