All these difficulties were enormously greater in days of primitive barter, before money and organized markets had been evolved. The difficulties of barter have been much elaborated in the literature of money. I shall recur to the topic in my chapter on the "Functions of Money." Part of the trouble arises from the "want of coincidence" in barter--the failure to find the man who has what you want, and who at the same time wants what you have. Goods have high or low saleability, depending, in considerable degree, on the _universality_ of the desire for them. They may have high _value_ if only a few rich men desire them, provided they be scarce. The paintings of old masters would be a case in point. Incidentally, the difference between buying price and selling price is often enormous in this case, and the making of a sale may well involve long and expensive negotiations. The difficulties of exchange here arise not alone from the limited market, however, but also from the fact that each painting is a unique, and a unique of high value. A good might have high saleability despite the fact that the ultimate demand for it comes from only a few rich men, if it could be easily subdivided and standardized.
Menger enumerates a number of circumstances connected with a good which increase its saleability. Among them are the following:
1. Widespread and intense desire for the thing (to which should be added, adequate wealth on the part of those who desire it).
2. Scarcity of the commodity in question.
4. Considerable development of the market.
5. That the demand for the article should be more than local.
7. That commerce between localities in the article be unrestricted.
8. That demand for the article be constant, not fluctuating, in time.
10. That it be uniform in quality, so that standardization is easy.
In general, Menger's list meets the requirements often laid down for a good _medium of exchange_. In general, to the extent that any commodity meets these tests, it will be _saleable_. Commodities will vary indefinitely in the extent of their saleability.
Starting with the distinction between value and saleability, and with the analysis of the circumstances affecting saleability, we may now undertake to see how money tends to develop out of a barter economy. Suppose that a man, in a barter economy, has a good of low saleability, which he wishes to trade for some other specified commodity. He finds no one who possesses the commodity he wants who is willing to trade with him. But if he can trade his article of low saleability for some other commodity of higher saleability, _still not the thing he wants_, he has yet made progress, he has got _one step nearer_ the object which he does want. It will be possible now, perhaps, to trade the new article, of higher saleability, for the commodity he wants. If not, he can trade it for some article of still higher saleability, which he can finally trade for the article he wants. By several indirect exchanges, he finally reaches his object. Incidentally, it is erroneous to distinguish money and barter economies as economies based on direct and indirect exchange. The barter economy may well involve much more indirection than the money economy, in many cases.