rodney, I've seen folks here get $500 over invoice easy. I've also seen very close 2nd hand accounts of $250 over invoice. PM me.
Finally, is there a reason you are not adding the dynamic handling package (and the adjustable dampers it comes with it) to your spec? best $1,400 we spent on the car. cannot recommend it highly enough.
2013 X3 28i, AW, Chestnut, Sienna, ZAP, ZCV, ZCW, ZDH, ZPP, DHP, rear view, park distance, cargo net (Wife's)
2010 Porsche Boxster S (Mine)