My niggas switched up the hustle, they moving amphetamines in Reno
A zero to a motherfucking kilo
It's 43 for a eagle
I guess them birds is red now

from Sean Price (Ft. Freddie Gibbs) – I Remember Lyrics on Rap Genius

Meaning

Gibbs’s friends ended their previous hustle and started selling amphetamines (likely cocaine or molly) in Reno, expanding from nothing to a whole kilogram of amphetamines.
After learning that the price for a kilogram or “bird” of heroin (aka red eagle) was only $43,000, Gibbs’s friends took the opportunity to switch products once again. Whereas before their bird/kilo would have been white, they now deal in birds of heroin/red eagle which means their birds are red. Clever wordplay.

Shouldn’t be confused with the “red bird”, slang for a type of barbiturate pill.

To help improve the meaning of these lyrics, visit “I Remember” by Sean Price (Ft. Freddie Gibbs) Lyrics and leave a comment on the lyrics box