It isn't so easy to determine if costs are covered. Suppose you have a store that sells rutabagas and phonebooks. You buy at wholesale prices of $1 per rutabag

It isn't so easy to determine if costs are covered. Suppose you have a store that sells rutabagas and phonebooks. You buy at wholesale prices of $1 per rutabaga and $2 per phonebook. You need a markup to cover the cost of rent, bond payments, volcano insurance, and heating oil. You could mark up each product by 50% or by $0.75 or whatever. You can do the same percentage, the same per-item amount of dollars, the same amount of dollars for the total of all items sold, or something else. If you sell rutabagas for $1 each and phonebooks for $5 each, does that count? You didn't exactly take a loss on the rutabagas, but on the other hand they didn't contribute toward paying for that volcano insurance. Maybe selling the rutabagas cheaply will bring in more customers, many of whom will buy overpriced phonebooks. If a rutabaga sold at $0.79 causes an average of 3.14 phonebooks at $8.05 to be sold, does that rutabaga cover costs?