I ordered my Flowmaster kit from Summit Racing, and had a local speed shop put my exhaust on for 100 bucks... I am happy with the purchase, install, and sound.
Personally... I wouldnt let Midas, Bandy's, Pepboys, or any of the other chain stores touch my car. About Ravin being better than Flowmaster or any of the other brands...
I asked my buddy at the speed shop I goto and he laughed... He also said the same thing as the other post(s) above, "They probably stock Ravin and/or get a really good deal on thier exhaust products, then turn around and over charge to make money."
I say find youself a speed shop to goto and stay away from chain stores... Just my opinion though (dont wanna get flamed on this bored)