Dual exhaust prices?

[trailguide2u]

Looking at Magna flow so far. Installed around 800.00 bucks. I can get a one time used single for 300.00. They put it on a 6.5 and did not like it. Any suggestions??? Performance gains or MPG info would be great..........

[Heartbeat Hauler]

I installed a 4" single on my 3500 and didn't really notice any performance gains per sey, but I did notice lower EGTs and it SEEMED like the turbo spooled up faster could be just the coolness factor. I think that it did help once I had the restof the Banks kit installed. Not sure if duals will hurt or help.
JP