FutureF1's B8 Audi A4

[FutureF1]

Well here she is. Bought her back in September. A real jewel. Only 55k miles from 2009.

Been thinking about doing some light modding. Definitely thinking of getting some RS wheels and a nice set of Bridgestones along with maybe getting the RS grille.

Currently looking at small things to give boost in HP and noise as some of the power gaps between gears can be pretty large. Not planning on taking it up to a track anytime soon but would like to have it ready if I ever decided to.

Had some questions for those of you in the know.

1). Why are CTS Turbo products so much cheaper than the likes of AWE or APR?
2). Will a CAI be worth the upgrade?
3). Should I blow the $600 to upgrade the ECU or go for smaller, less expensive upgrades like a downpipe/CAI?

Thanks!