$15,500 would be good offer for them. If they turn it down, then tell them no, that you will look elsewhere.
I paid $17,000 OTD for my 11 model but it had no accessories on it.
Just like Crossroads said: you have the upper hand on this. They know it and now you know it. Do not squabble with them, just walk
They will call ya
When I go to get a bike I tell them I am not here to squabble give me your best price. I either except or walk.