I find it hard to believe that the brake pads are in good condition if you have a metallic sound coming from the brakes. Who inspected them? Did they check the rear brakes? If the rear brakes are drums did they remove the drums and inspect the brake shoes? You can check the from brake rotors very easily. If you can reach through the wheel, you can feel to see if the discs are smooth are have scoring (grooves worn into the rotors). If not you can reach behind the wheel and feel for grooving on the backside of the rotor. If you have any scoring, then the front pads are definetly worn. If not make surre you check the rear drums or discs depending on what you have. I believe the base model of your car has rear drum brakes so it is critical that the drums be removed and the brake shoes inspected as soon as you can.
If the brakes are fine the drums should not spin so I think that is your problem. I suspect strongly this is the source of the noise. I know money may be tight, but $80 is a cheap price to pay for something that may save your life. Brakes are not the thing you want to neglect. It is not too hard to replace the brake shoes on the rear although it will be a bit more dificult than the front and in any case you'll need to have a machine shop turn the drums to do the job right.