$9.50 - Crack - Francis Bloomerstein
$12.00 - Meth - Diana Greenfield
$15.00 - Heroin - Ella Hasselhoff
$18.00 - Coke - George Bush
$19.00 - Ecstasy - Dave Jacksonberg
#1 tells you Francis' last name isn't Jacksonberg
#2 tells you the highest and lowest priced drugs
#3 tells you the price of the heroin, and the last name of the buyer
#4 tells you the last name of the woman who bought the meth; at this point you should know all the prices of the drugs
#5 tells you the items bought by Bush and Dave were ecstasy and coke (not necessarily in this order)
#6 tells you nothing, except that Ms. Greenfield is a total slut
#7 tells you the first name of the coke buyer, and, with that and #5, you should be able to determine the last name also, and the first name of the ecstasy buyer. you should now know everything about the coke buyer.
#8 tells you the first names of the two lowest priced drug buyers, and with that, in combination with the fact that Ms. Greenfield is a woman, and Francis is a male name (female version is Frances), you can determine everything about the meth buyer; then, referring back to #1 you can determine everything about the crack buyer; then, through process of elimination, you can find out the first name of the heroin buyer and the last name of the ecstasy buyer.