32 THE MODEL STOCK PLAN the class of trade it is catering to will most willingly pay. We must keep in mind that unless this type of information is used discreetly, it may invalidate the greatest profit-making forces of the Model Stock Plan. 4. Studying what other successful stores are selling, close examination of their goods, their prices, and their apparent volumes at these prices is, as we know, almost sure to be extremely helpful to us.2 By checking the different stores at the different levels of trade, we get a rather definite line on what is the best-selling price level for each of them. With these steps in research and reasoning, we now have our possible price limits rather closely ascertained. We have made this progress not by traditional thinking and opinions but by really scientific methods. Having applied ourselves with concentration to the question of fixing our prices, we have by now come near to testing our prices, which is far better than making them, as they are now for the most part made, by rule of thumb. Instead of setting our prices by what the producer asks, we set our costs by what we can afford to pay for the established price lines and, therefore, tend always to obtain better value for our customers at the prices they will most willingly pay.? It is recognized by successful business men that our most profitable job is to buy for customers and not simply to have in mind selling to them. This method of finding the right prices is not difficult. It requires, to begin with, somewhat more effort than does arbitrary opinion, but it is worth effort far beyond what it 1 Of course, we know that price ranges of different stores overlap, and one range in one store is another range in another. And we do need the records, instead of guesses or memory, to know what we have actually sold the most of. But we must have in mind that these records may be wrong. We need to know how records may mislead us. 2 Tt may be, of course, that all of our competitors are inferior to us in their knowledge of the price levels that pay best. But unless we are already using the Model Stock Plan this is most unlikely. 3 The Model Stock Plan includes another very great aid to avoiding errors in establishing the price lines, as is explained in Chap. IIL, p. 46. Essentially this consists of establishing one outstanding value in each class of goods at each price, comparing each item in our whole line with this item, and then shopping competitors closely on this item.