Profit is also related to your pricing, shrinkage, operating costs, sales volume and raw material costs. Look, with so many factors, you may only count one or two, so this is just an estimate.
For example, let's calculate now that a catty of trotters 18 a catty, the brine will shrink by two or two. In addition, the production cost should be 1 yuan, and at least 2 1 yuan can be recovered. In addition, your other renters, etc., may take 23 years to return to their books. If you sell 33 kilos, the profit is 30.3%. If the duck neck is 6.25 yuan per catty, if it shrinks by 5 taels, then the real cost of a catty is 12.5 yuan, and the production cost may reach 15 yuan, then the seller is 39, and the profit is 6 1.5%.
In addition, there are marginal costs. With the increase of sales, the cost will be smaller and smaller, and the profit will naturally be higher.
And so on.