When I sell something on a forum, I usually look at the sold items on Ebay and see what they went for and sell them to a forum member for a little less. Unfortunately, there don't seem to be any sold f6b mufflers. The closest thing I see is "like new" Goldwing pipes that went for only $105, and some slightly pitted turn down tips that went for $65. Since your tips are probably nicer, I would think the most you could hope for on Ebay would be $200 for the exhaust and tips. If I was selling them, I'd probably offer them to forum members for $175 plus shipping and then put them on Ebay if they don't sell here.

http://www.ebay.com/itm/Honda-GL1800...p2047675.l2557
http://www.ebay.com/itm/Chrome-turn-...p2047675.l2557