In this case, your gonna get what you pay for. I do recommend piecing together a kit, piecing together a kit without the headunit can run you between 700-900 dollars. And the head unit can be found for 700-800 also. But with this you will also have to buy new injectors, stronger fuel pump, and larger maf. Before install, I have heard of guys piecing together complete kits for 1600-1800. I would not recommend paying 5k for a complete kit that has the same items you can piece together for a third of the cost.
Sonic blue 04 GT~~bolt ons- headers, steeda tri ax, hi tech stage 2 cams coming this winter.