Prices such as are indicated here were dismissed by the earlier economist as mere economic curiosities. John Stuart Mill has something to say about the price of a "music box in the wilds of Lake Superior," which, as he perceived, would not be connected with the expense of producing it, but might be vastly more or perhaps decidedly less. But Mill might have said the same thing about the price of a music box, provided it was properly patented, anywhere at all. For the music box and Shakespere's skull and the corner in wheat are all merely different kinds of examples of the things called a monopoly sale. Now let us change the example a little further. Suppose that the monopolist has for sale not simply a fixed and definite quantity of a certain article, but something which he can produce in larger quantities as desired. At what price will he now sell? If he offers the article at a very high price only a few people will take it: if he lowers the price there will be more and more purchasers. His interest seems divided. He will want to put the price as high as possible so that the profit on each single article (over what it costs him to produce it) will be as great as possible. But he will also want to make as many sales as he possibly can, which will induce him to set the price low enough to bring in new buyers. But, of course, if he puts the price so low that it only covers the cost of making the goods his profit is all gone and the mere multiplicity of sales is no good to him. He must try therefore to find a point of maximum profit where, having in view both the number of sales and the profit over cost on each sale the net profit is at its greatest. This gives us the fundamental law of monopoly price. It is to be noted that under modern conditions of production the cost of manufacture per article decreases to a great extent in proportion as a larger and larger number is produced and thus the widening of the sale lowers the proportionate cost. In any particular case, therefore, it may turn out that the price that suits the monopolist's own interest is quite a low price, one such as to allow for an enormous quantity of sales and a very low cost of manufacture. This, we say, _may_ be the case. But it is not so of necessity. In and of itself the monopoly price corresponds to the monopolist's profit and not to cheapness of sale. The price _may_ be set far above the cost.