_How the Prices of the Goods are fixed when they are sold in Various Combinations._--How do these articles get their valuation when they are tied in bundles containing all five of them and the bundles are sold unbroken? In essentially the same way as when sold separately. Article A, we will suppose, is one of the necessaries of life and is to be had by itself in the market. Article B represents a comfort, and C and D are luxuries. The bundles are so made that A and B are often sold together; as are also A, B, and C; and A, B, C, and D. A purchaser may have at his option the first only, the first and the second combined, the first three, or all four. Article A, when it stands alone, can be had at the natural or cost price and in quantity sufficient to supply the wants of all classes of buyers from the highest down to the class which will take it at ten dollars--the cost of making it--but at no higher price. Any one can have the A either alone or tied to other articles at this price. One who buys A and B in combination will pay for article A only the same price that it commands when sold separately; and since he buys B, the utility of which is less than that of A, at ten dollars, it is clear that he gets A for less than it is worth to him, but the ten dollars may be all he would give for the B. This man is not the marginal purchaser of A, for in buying it he realizes a consumers' surplus; but for the article B, which is tied to it, he may pay all that it is worth to him. For that he is a marginal purchaser, and as such he gets no consumers' surplus out of it. What he pays for B will just suffice to buy something else which is equally important to him. The price of this bundle of two articles is ultimately determined by the cost of the two components, which is twenty dollars, and enough of each component is made and offered in the market to supply the wants of a class of persons who will barely decide to take it at the cost rate. The class that hesitates at taking A will not consider B, but the class that hesitates at taking B gets a clear benefit from buying A at the price that expresses the utility of A to a poorer class of persons.