This should help give you an idea regarding costs for parts:
http://e-partssales.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=P&Category_Code=987int
As for labor...it's gonna be expensive...probably $1,000's.
If you'd ordered/got it from the factory with the optional PCM cost is:
PCM 2.1 (code P16) $2,970
PCM 2.1 w/extended Navi (P23) $3,175
Always soooooo expensive to go the Tequipment route!