Price and purity are estimated for powder cocaine, crack cocaine, heroin, d-methamphetamine, and marijuana. The annual predicted price of one expected pure gram of powder cocaine increased in the years 2000-2001 after having held steady at the end of the 1990s. This trend was mirrored by coincident decreases in expected purity. For the national indexes, these trends were reversed shortly thereafter, and these new directions persisted through 2007. Beginning in the late 1990s, trends for the estimated adjusted price time series for crack cocaine generally tracked those for powder cocaine at the national and city levels. For heroin, the national indexes for the annual predicted price of one expected pure gram steadily decreased after local peaks in 1990, with the possible exception of small increases in 2004 and 2006. Since 1997, expected purities at the national level generally decreased from year to year. For d-methamphetamine, there were annual price peaks in 1995-96, 1998, and 2006-2007 coincident with the introductions of methamphetamine precursor chemical regulations. In between these peaks, estimates of adjusted prices declined steadily. The expected purities mirrored the trends in estimated prices. For marijuana, trends in the estimated price of one bulk gram have varied across quantity. A comparison of 2002 to 2007 shows no change in price at the lowest quantity level, a 10-percent decline at the medium quantity level, and a 50-percent decline at the highest quantity level. 25 figures and 20 tables