Knowing what I know now...I would definately estimate the price without including the sunroof. I know someone else posted he tried trading in an H2 with aftermarket, and the dealer killed the price bcs of it. It's essentially worthless as far as value goes (my 2cents). If I had known at the time I purchased mine, I'm sure I could've knocked some more off of the price.
I would see if he has the original air intake so you can return it to factory if you needed to. Same goes with the tire carrier. The aftermarket swing-away isn't even the SMA/GM approved one. Ask the seller if he has the interior mount with all parts. While you're at it, make sure the spare is in good shape...mine had a bad scratch on it because the interior mount was missing a few pieces...and it was flopping around when I drove it off the lot (they sent me parts to fix it later).
Lastly, check on when the vehicle was originally put into service/the purchase date...cause that will dictate how much longer you'll have on the warranty. You'll need it to make sure all the TSB's are taken care of and any bad parts are fixed...
Oh, you also have the compressor in the back so see if he has the compressor hose as well as the first aid kit etc...
Keys for the roof rails, owner's manual.
The price is better than what I paid...but I purchased mine a year ago... Just check edmunds, kbb, and nada for some estimates...take a little off for the aftermarket stuff...if it looks right...then do it....
p.s. - I'm not trying to sway you from the purchase...I just like knowing all the facts before jumping in....good luck!