Why Money is Better Than Barter
Sep 3, 2018 · 1 min read

For N prices, there are N² combinations.
N of them are a price of 1.0, since the price of a uniform good versus itself is 1.0.
Half of the remaining of the prices are simply the inverse of the opposite price along a diagonal axis.
The number of prices to keep in mind can be expressed as N²-N²/2-N/2, (N²-N)/2, or (N-1)(N/2).
If almost everyone uses money, the number of prices to track are just N-1, where N is the number of goods including the monetary good.