You should compare their offer to what you can read on http://www.carlemon.com/lemonstat.html.
Furthermore, any current incentives (rebates, etc.) don't enter into the picture at all.
I believe that the dealership has a limit on how many buy backs they are allowed without jeapordizing their 5-star status or whatever, but that the funding comes from the 'factory' not the dealership. That's why the incentives don't figure in.
Consider yourself lucky that you have their offer to consider; now you just have to evaluate your alternatives.