This is very expensive.
Here are the prices for the last 5 levels:
- 16: ~23,000
- 17: ~33,000
- 18: ~48,000
- 19: ~69,000
- 20: ~99,000
Here is how I made most my money in the end game:
- Get a manager in your branch that is min. lvl 9
- Farm glacial sharks (i.e. Narwhal, Porbeagle Shark, Greenland Shark)
- At first, save their meat until you can level them up to lvl 10. (This will also give you the achievment for the Diamond Cooksta Rating, if you don't have it yet.)
- Once a specific sushi recipe is at lvl 10, spam it in your restaurant and in the branch. The branch makes roughly 22.000 a night if it's fully stacked with Narwhal lvl 10.