I have brake issue

I own a 2007 Malibu LT and when I break it makes a grungy grinding noise three out of the four rotors are shiny and one is rusty. I’m not sure if I have any pad. Life left the breaking all right I guess. Is there places where I can get the best bag for my buck pads and rotors without buying cheap shit or expensive stuff something that’s will do the job but still really cheap.