I don't know if it helps you since you have different shops around, but around here for an h pipe flow master 40s and dual 3 inch chrome tips I was quoted 550 Dollars. 
__________________ 2000 3.8 Manual Coupe
K&N FIPK2 intake, Dual Flowmaster Orig 40s, 2.5" Diameter H pipe, 3.5" Chrome tips, Carbon Fiber Rear Bumper Inserts,Side Mirror Ponies,Black Mustang Windshield Banner, Black LED 3rd Brake Light, 245/45/17 DZ101 Dunlop Dirreza Tires, 17" Brushed Aluminum Cobra Wheels, 8" Chrome Shorty Antenna, FRPP C-Springs,Mustang Liscense Plate Frame, Sound System, Gps, Billet Interior, Mach 1 spoiler, Cobra Headlights, HID's, Red Calipers, 35th aniv black leather seats |