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1.
often heard in the phish lot or the lot of a festival or big music event. it means 3 balloons of laughing gas for 20$. its often the nitrous gangsters or mafia yelling this cause hippies and festy heads with tanks sell for a cheaper price.
nitrous ganster: 3 for 20 have ya money
festy kid: will you do 4 for 20?
nitrous ganster: no 3 for 20
by wookie foot July 11, 2011
 
2.
Three grams of bud for $20, instead of $30. Only the good dealers through this
guy: "yo man can i get 3 for 20?"
dealer: "shiiiiiiit aight"
guy: "preems"
by Budski April 18, 2007