Adam, I just got off the phone with Medved (for those who don't know, Medved Autoplex is Denver's Hummer dealership).
The factory chrome grill is $455.00. The factory black grill is $399.00. Go figure.
So trading straight across is really not a bad deal. I just missed getting
this black grill from a guy who just sold his black grill after replacing it with a chrome grill. As always, it's just a matter of taste.
BTW eBay seller
factorypartsguy (evidently a Hummer dealership in Salt Lake City) sells the OEM black grill for $325 + $25.00 shipping.
update: GM Parts Direct sells it for $324.00 (cost of shipping unknown). Part #12499002