How much Should an exhaust install cost?

I have a quote from a local shop to install a 2.5" exhaust from my LT headers back to rear valence with H pipe and 40 series Flowmasters for $325. The down side is they are not mandrel bends. I would guess with you supplying those parts it should run you $160 max.

I was charged $70 on my neon for a custom made front section and rear section...but then, it wasnt mandrel bent either...they also charged me $70 for my new muffler...so $140 total

I took my car to a local "high performance" muffler shop in Southern Maryland, "Insane Exhaust". I had bought the Magnaflow kit from Summit, and did most of the installation myself. The only thing I asked them to do was connect the x-pipe to the headers, and to use ball style joints at the headers. One week and over $300 later I had my exhaust system hooked up, with the cheesy 3 bolt flanges that always leak. They did use preformed mandrel bends, but they were only about a foot in length and weren't even stainless. Needless to say I was not a happy customer. Eventually I plan to go back and make them replace the crappy 3 bolt flanges with ball and sockets that I paid for, but I have bigger problems with my motor at the moment. It's really hard to find a good shop. Try to get references from happy customers, but even this isn't a guarantee. I've seen other cars Insane Exhaust did that were incredibly well done, but they did the whole system and charged around $800. I guess they think anything they do is worth megabucks.

Most muffler shops cannot make "mandrel" bends. the typical bending machine in the shops do no insert the piece required into the tubing before bending, you are probably in the $2-300 range. Remember, the owners of these shops are trying to make a living and have a lot of expenses just to operate their shops.