js9234 - Did you just have the muffler welded in? If you did and didn't have anything changed from the muffler back, you still have the resonators on. When I had my 14" magnaflow and y-pipe put in, I left the resonator. I took it off a few weeks ago, and holy crap its loud and I get some major drone at 1500-1700 rpm. But, I like how it sounds now.
To the topic, I paid $150 for install. Bought my 14" and y pipe and had an exhaust shop do it. Not bad at all. Beats the $1100 I paid for my Borla on my 2010 1500.