Although it's annoying, this may not be cause for alarm. Metallic particles in so-called semimetallic brake pads may be the culprit. Pads made of asbestos or of nonasbestos organic material tend to stop more quietly. But the use of asbestos in brake pads has decreased in recent years. Using antiseize compound and, where applicable, the correct shims on the back of the pads can usually reduce brake noise.
Prices vary from car to car and shop to shop.
After the job is finished, you should break in the brakes. Brake gently for the first 200 miles, avoiding panic stops, if possible.