I called them and asked if they still had the sale going on. There is a set number they are selling at that price, and I didn't call soon enough for the coated ones, they sold out.
I would for sure get it coated before installing it. Totally worth it, keeps them looking so much cleaner, helps reduce engine bay temps, and obviously will flow better.
I might have been under the wrong assumption. I thought that coating the outside had a similar effect as wrapping it. Makes sense I guess that you would need to do the inside...