I'd start in the mid to high 4k range since that is just under the blue book value. I'd ask yourself what your bottom line is and add a few hundred for negotiating room.
The 2011 bikes are UCE and riding at 65-70 is no problem for them after they are broken in.Whether this is good for highways has more to do with the highway than the bike.For instance, I-17 from Phoenix to Flagstaff has stretches with a posted speed of 75 mph.That means everyone is driving at 85 + mph including the big 18 wheelers.IMO, that's not good company to be in when your bikes max speed is 80.