My break light is on and my breaks went down to the floor when I pressed on them on 2000 Nissan Altima

What can it be and
How much should it cost

Asked by for the 2000 Nissan Altima
Sound like a busted brake line or your master cylinder is bad, but you live in Ny, I will say rusty brake line, hard to price !!!
no,no,no, check your brake fluid level, if it is low most likely you need new brake pads.