i have a cheap 2.5" custom vibrant exhaust i can sell for $150.. its half stock piping and new piping/muffler where our pipes get small it will give you pretty much the same results as the regular magnaflow.. for less money.. i also have an extra MS3 resonator you can weld in if you want really quiet low pro power..
for my MS6 ive had the CS, CPE, Magnaflow, Vibrant custom and currrently running a Magnaflow 3' custom.. the best flow is my current setup, best stealth power was the vibrant.. the others were nice flow but, too loud and the magnaflow they sell was ok.. but, almost all were overpriced for their quality and construction.. go get a local shop to make one or keeping looking for a used one to pop up..