I've had that line on repeat for like a minute and I can pinpoint. I don't think there's any conclusive answer unless Jay comes out and clarifies it himself.
It could be "cheap keef" "chief keef" or "GP" and they all make sense (to an extent)
For what it's worth, after he said that line, he kinda did a Chief Keef flow when he said "out a spite, I just might flood these streets"
If I had to guess, I'd say it's "I might buy a kilo for GP"
Cool throwaway track though.
Some of ya act like ya never heard Jay Z rap before. (not speaking about you)
Jay is a master of entendres...
Notice how he purposely pronounces the word "chee..." so it can be interpreted as "cheap" or "chief"...
He could also be saying "i might buy a kilo for 17k" (17 being the age of chief keef, to flood the streets)
or literally saying "i might buy a kilo for chief keef and give it to him so he can go out and flood the streets"...
It's a backhanded shotout... he's positioning himself as some sort of drug kingpin to his little man, chief keef but also using chief keef as an example of wrecklessness and ignorance... pretty much saying "if i wanted to commit a real crime, i have enough money to distribute drugs to the chief keefs of the world to really fu*k sh*t up".