Ok he said the cops stole rent money. Does he pay his rent in cash.

Check out who owns the building that he pays rent to. Then how much is his rent and does he always pay cash.

He keeps a months rent in the store all month long until he has it all?

He is lying

What else does he sell besides food and cigs?

I can go to a bodega in Brooklyn. Once they know me I could by anything there.

They are the fences of stolen goods in that neighbor hood. Maybe that is what all the cash is used for.

Maybe he does a lot of illegal action.