Baking soda
It's usually used for cleaning/cooking purposes, but it can act like cocaine for the broke and misfortunate living in the ghetto. It's easy to find at your local stores; much less expensive than cocaine. It doesn't have the same effects as cocaine, but people can only pretend.
"I'm in love with that baking soda!"
"Look at all this baking soda"
"You have the baking soda?"
"I got baking soda!!!"