A couple other thoughts. The 2010-2013 GSA’s (2010-2012 GS) had a way smoother engine (Cam-Heads?). I had a 2007 and it was great bike, but not as smooth.
You can check AdvRider for price comparisons, but need to factor in condition and location. Mileage is not the only indicator on adventure bikes.
It looks like there is a clean, nicely setup 2009 GSA out in Dexter for a little less. https://annarbor.craigslist.org/mcy/d/dexter-2009-bmw-r1200-gs-adventure/7121916129.html