that seems to be the $$ on tunes... thats about what i paid on my jeep. the GXP's i was looking at range in price from 8,9xx (05)to 11,xxx(06)
Price is about right
http://www.grandprixforums.net/my-06-gp-gxp-72403.html OBX headers, TEP tranny cooler, ls1 IM fuel rails and injectors, ls2 TB, ls7 MAF, full custom exhaust, Quad retro headlights, full out front and rear suspension work, tuned by HPT by me 8====>