"A more recent study using a demand-side approach estimates that the annual retail value of the U.S. methamphetamine market is between $3 and $8 billion, with a best guess of $5 billion.12 The margin of error is large because the footprint of methamphetamine use does not match the footprint of the data collection system. Methamphetamine use in the United States is concentrated in certain regions, and it is not primarily an urban drug, whereas data collection systems are centered in urban areas. Moreover, because there have been dramatic shifts in methamphetamine consumption and production during the past decade, estimates are highly dependent on the year analyzed. While there are considerable uncertainties, the amphetamine market is clearly smaller than the cocaine and cannabis markets in North America, smaller than the cocaine market in South America, and potentially smaller than markets for other drugs elsewhere in the hemisphere as well. However, data are not available to provide a detailed analysis for all regions."

Source

Organization of American States, "The Drug Problem in the Americas: Studies: Chapter 4: The Economics of Drug Trafficking," 2013, p. 12.
http://www.cicad.oas.org/Main…