The C3 will run you $650 shipped new. ~$450 used.
The NW single cai will run you around 600 new, SL 55 setup around $400 used (buy tubes/horns separately)
Eurocharged had a tune special the other day, $399.

So you're looking at about $1200 for used parts, $1800 new, depending on the sales.

I would go with the dual NW CAI instead of the single though. I ended up with the SL 55 intake setup because I didn't want a lot of SC whine, but if you're into that I would go with the max HP/whine available for the NW Dual.