Bag of bags. /n noun
A bag containing other bags filled with units of narcotics for sale individually.
A dealer may keep all of their individual bags pre-weighed ready for sale in their larger "bag of bags"
Junkie: got a 10 bro?
Dealer: I aint your bro, jerk. Hey Matt, pass me my bag of bags, this guy wants summat
Matt: Get it yourself you lazy prick
Dealer: Here ya go buddy, take your pick from my bag of bags