Crack is unique because unlike other forms of cocaine which tend to be extremely expensive, crack comes in small and low-priced packages. In the United States, crack cocaine is often sold in small, inexpensive dosage units frequently known as a "blast" (equivalent to one hit or a dollars worth), “nickels”, “nickel rocks”, or "bumps" (referring to the price of $5.00), and also “dimes”, “dime rocks”, or "boulders" and sometimes as “twenties”,"dubs", “solids", "slabs" and “forties.” The quantity provided by such a purchase varies depending upon many factors, such as local availability. A twenty may yield a quarter gram or half gram on average, yielding 30 minutes to an hour of effect if hits are taken every few minutes. After the $20 or $40 mark, crack and powder cocaine are sold in grams or fractions of ounces. At the intermediate level, crack cocaine is sold either by weight in ounces, referred to by terms such as "eight-ball" (one-eighth of an ounce) or "quarter" and "half" respectively. In the alternate, $20 pieces of crack cocaine are aggregated in units of "fifty pack" and "hundred pack", referring to the number of pieces. At this level, the wholesale price is approximately half the street sale price.
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