Looking for reasonably priced Vet Clinic for sedation of dog for grooming

We recently took in a 16 lbs male maltipoo that is badly matted and doesn’t react well to groomers that try to shave him. We have taken him to the vet and they prescribed Gabapentin but that didn’t calm him down enough because the mats cause him so much pain.

I am looking for a vet clinic that will cost around $150-200 or less that will do the sedation and grooming. The one that pet-smart referred was almost $400 which is too expensive. I spoke to a friend and he said it should be based on the dog’s weight and not cost THAT much for 16lbs.

Any recommendations in the Houston area and surrounding will be greatly appreciated.