I'd suggest to do it yourself. The secret is to use Penatrating Oil (I found the one by Valvoline to be a great help! $3.99). I used it on the bolts, and let it sit. The bolts between the B-pipe and exhaust pipe were easy to unbolt. But the bolts between the cat and b-pipe were a *****, so I took the cat off with the b-pipe attached. Those screws were easy after some penatrating oil. I let it sit for an hour while a friend drove me to the store to buy a Craftsman socket (guarnteed for life!) Once I got back, the bolts camed off with ease. Now I had the b-pipe and cat attached in one section, and the exhaust piping in another section. I had sprayed penatrating oil on the bolts before I left. I had my dad stand on the cat while I used t long socket wrench to break the bolts. They came off with ease (for 138k miles of use and heat, I was suprised). As for the hander, use WD40, they'll come off the hangers with ease.

Basically, do it yourself if its a bolt on system. If its universal weld on, then have a shop do it.

As for me, I bought an RS*R cat-back, but it didn't fit. It was the last one in the United States brand new, and I didn't want to send it back. I had Midas customize it, and that worked out pretty well. I just had it installed on Monday, they did a good job, and didn't charge as much as other shops. They eve had room for my 3" dropped accord on the racks. Other shops said to raise the car. The total was $109 for the labor. Plus some parts (I guess bolts and welding), and tax. Final total was $128. I'm happy.