Find out what the invoice price is - which I think is in the $5900 range. Offer him that plus $100. Contained within invoice is also a dealer hold back provision, meaning he gets some of that paid back to him from the manufacturer as a profit later in the year. Don't pay any prep/delivery or paperwork fees. In this case, OTD would be whatever you offer plus sales tax if any plus licensing. If the offer isn't accepted, thank him leave him your phone number, and drive to the next place. Feel free to talk to the sales manager directly - you don't need a salesman that gets commission if you already sold yourself on the bike.
OTD is a little decieving on a forum like this, because taxes and fees vary state to state. I might buy a bike at $6600 here and get a good deal - you might pay the same amount and be getting the short end of the stick.