Depressed prices and elevated purity levels often signal increased drug availability. Cocaine prices at the kilogram level have remained relatively low between January 1991 and March 1994. During the same period, the national average purity of cocaine has remained relatively high. Heroin prices and purity levels are much more difficult to pinpoint, but heroin prices have declined at the low end of the price range since the early 1980's and a wide variety of sources and an abundant supply of heroin have led to high purity levels. Marijuana prices and potency levels have increased during the past several years. Although LSD prices have fluctuated in recent years, overall prices for this hallucinogen have remained relatively low. Primary importation and distribution centers for cocaine include Houston, Los Angeles, Miami, and New York. Detailed price and purity data are tabulated for cocaine, heroin, marijuana, methamphetamine, LSD, PCP, MDMA, psilocybin, diazepam, counterfeit quaaludes, and other drugs. 22 tables