Who are the good affordable exhaust vendors?

American Muscle, Ninosport, Summit Racing, Steeda, alot of people are great to deal with. Ive had good experiences with ADP performance. I think they are fairly new but they had a good deal on the catback I was looking for.

A UPR x pipe is very affordable and is a quality peice. You can get one from UPR for around $160-$170 or so without cats. I matched my UPR with a Mac Flowpath catback and it sounds sick, but alot of people say that chambered mufflers (like Mac, Flowmaster, Spintech) dont sound good with an X pipe.

You really couldnt go wrong with Magnaflow Magnapacks or SLP Loudmouth-II's. Loudmouth I's are seriously loud and did I mention they are really loud?
 
From personal experiance, MAC sounds great, but their coating sucks, its not really worth the cheaper price as I will be buying a new catted midpipe only 3 years after installing mine.

My SLPs however are on their 2nd winter of driving and not showing a sign of rust or pitting, the price is a bit higher (But still cheaper than some) and probly the best quality item I have bought for my car so far.

My BBK shorties, while the fit is awesome and the price was outstanding, they are a little sloppy with the weld splatter (No biggie if you have a dremel and a little bit of time) I'd still suggest them though.

I would suggest MAC IF they sold a SS version of thier products (and then have them ceramic coated myself)

UPRs exhaust stuff I have heard nothing but good about even from people who won't buy their other products.

That's the only input I can give as far as quality to price goes. Some decent sales sites were allready mentioned.