So obviously this can be improved upon to just barely survive 14 days, however mine uses a bit of setup at the beginning of the day and from there its pretty smooth sailing. So I start by purchasing 50 Cups, 20 tsp of Coffee, 10 cups of Milk, and 20 tsp of Sugar. Then for my recipe, I set Coffee at 2.2 tsp, Milk at 1.2 cups, and Sugar at 2.2 tsp. Then I set the price to $1.90 and start the day. When purchasing for the following days, its important to be fast, since you can sometimes get ghost buyers, that buy coffee before they're even supposed to be able to. Its hard to follow an exact formula for what to purchase daily, since if you get bad RNG, you could end up not selling out. But the goal is to only buy Milk unless you need to purchase coffee and sugar. When you get toward the end of the game, you'll get what I call 5 cup strat, where you've only got 5 cups left, speeding up that day. Just make sure to refill your cups, you can just buy 10.