$130 for the K&N filter, dont pay anymore, as its not worth anymore than that.
$50 to fit cold air, bargain! i paid $50 to buy 3" heat protected brake duct pipe, and then i drilled the hole myself.
make sure they dont **** your ABS unit up, if you do have ABS??
its fully under the air box, they need to move the wire loom in front of airbox, drill a 3" hole (biggest you can fit) between headlight, and airbox, and feed the pipe to front bumper hole.
a new airbox costs $70, so dont drill it, feed the 3" pipe into the original hole, your duct is heat protected, so the radiator wont affect the air temp much anyhow.
i could show pics of mine if i had a digi cam, i dont, so sorry mate
YES, there is benefits, not so much HP at the treads, its more throttle response.