I just took another look at that ebay auction... Assuming you can buy a new CTS-V for $47k and can do a lot of the work yourself, this package is a bit overpriced. Ported heads should cost you around 1600-2500 (AFR 205 Heads, not LS6), you can then pick up a performance camshaft and upgraded valve train for <$1k, get a LS2 intake manifold/fuel rails/throttle body (these are all 90mm, just like the F.A.S.T. manifolds but are a fraction of the cost) for <$1k, exhaust shouldn't run more than $1k... you'll need a tune so figure another 500 and you're still under the $62k this clown wants. You probably got a faster car too.