You don't have to know at what price the drinks are sold. All that matters as the government is that you know how much is being moved around. Then you charge each link in the chain appropriately. The rest works itself out in the market.

I disagree with the legislative approach, but just think of how much cheap/free labor the war on drugs supplies. A war on sugar would keep those numbers up! Good job boys, promotions all around!

In the more boring dystopia, the disincentivization would lead to poor quarterly financials and cause the same movement in the industry. Nobody is pumping out cola at a loss simply because it's their passion project.