It means that, contrary to the predictions of the doomsayers on the left (who have predicted shortages of everything from oil to copper and other metals), commodity prices, when adjusted for inflation, have remained steady or fallen over the past 30 years. In a reasonably free market, there is no "ripping off" of either party -- the buyer and seller agree on the price. A significant percentage of the absolute price increase over the past decade can be blamed on the government, due to higher gasoline taxes, and to environmental mandates requiring refineries to produce special formula gasolines for specific markets. Instead of mass-producing one type of regular unleaded, to be sold across the country, refineries must make smaller amounts of many special blends. This increases production costs, and also increases the risk of price spikes if there are facility problems at a refinery.
I understand what your saying and agree with most of it; even though you haven't answered the question directly.
But if that's true, then why not a gradual shift in price?