Shaving a pets coat requires skill. Shaving down a matted pet requires a tremendous amount of skill and time. It takes considerably more time depending on the intensity of the matts to shave down a matted pet. Time is a key factor in pet grooming. Also the propensity for your pet to be hurt or injured because of the matts is very high. In order to be able to shave off a matted coat, the groomer must get under the matts down to skin level to successfully remove them. This takes time. Groomers charge for their skill and the time it takes to complete a groom.