Your going to have to shop... Fuel moto, especially if you want to buy as a stage package. Dennis Kirk, RevZilla all good even better when running a special. You might have to wait a month or two for best pricing. We're going into the hot season so have your credit card ready.
Where is the best place to buy a new exhaust for the best price?
There's no smoking gun here. Figure out what exhaust you want first (headers and slip-ons, full system, what brand, etc) and then shop around till you find the best price with shipping included.
I've been using Revzilla for most of my non-HD parts. Even if they aren't the best price, they will price match, and still do free shipping. They have done every price match I requested, shipped for free, they had everything in stock, and I had every item within a few days.