I have a great relationship w/ the shop that did mine and they have done exhaust work on probably 4 of my cars, and any work that I cannot do myself or don't know how (brakes etc which I want to learn ASAP). I was shocked when I got my bill. It was $175.00 total. $100 for labor and $75 for alignment. The mechanic told me straight up this was an easy job for him and took just over an hour for the install and that's it. I was super happy about it but I don't think that's the norm. OP if I were you I'd check around for at least 3 quotes.
2012 black on black GT Premium Auto 6R80 - 400A
20 x 8.5" AR Torq Thrust M - BMR springs & Koni str.t shocks - GT500 mounts - J&M LCAs - CHE reloc brackets - J&M panhard - General GMAX AS3 - GT500 axel backs (no resonators) - GT500 spoiler - MMD tail light trim - Roush side splitters - AM upper/lower billet grill - Bama 93v2R tune - Airade CAI