iemok,
Definitely below dealer invoice. Search through the posts to find the thread which will give you an ID an password to the GM Buypower site, there you will find the Invoice, Dealer Invoice and GMS pricing for GM Vehicles and their options. With the way the dealers are selling these days, you should be able to have a starting price at or just below dealer invoice, then add the rebates. I know that the GM in the Driveway certificates, search for that thread to, is a good deal and puts you at or near invoice before rebates.
When I bought my 02, I got $9000 off MSRP, which was all the rebates and everything, not sure because the dealer said that any AV in stock was $9000 off MSRP, which included any rebates, so I am not sure what the starting price was.
I think you should be able to pick up a nicely equipped Av between 28 and 30 K.
Robert