you need more than the unit itself to have any gains from it...
you need at least
all the piping - alone, this will cost you at least 500 for good piping
boost controller \
belt to drive the s/c
there's probably a whole lot more you need too, but thats all i can think of.
and a whole hell of a lot of time on your hands to make it all fit under the hood.
i know about the piping... i have a friend who can do that too, an intercooler, upgraded fuel delivery, all of that, i just really don't know about the mas airflow sensor, or the ecu... what do i need to do there?