They don't even need to go that far. They can just ration supply, forbid stockpiling and fix the price to artificially low levels.
This was occurring as recently as last year all over the world when commodity/food prices spiked. Anywhere you see black markets, you can find rationing and price fixing nearby.
The reverse is often true as well. Anywhere you see rationing and price fixing, you can find black markets nearby, assuming the distortion is high enough.
Yes, seems like trying to stop free markets from developing is just like trying to hide information or keep a theatre free of ringing phones. It can be tried, and sometimes even successful, but gosh it's a lot of work.
This was occurring as recently as last year all over the world when commodity/food prices spiked. Anywhere you see black markets, you can find rationing and price fixing nearby.