There's an auction running now with a stormbow that has better mods than the one that you have there, and it's Q9. But the starting bid on that thread was 20k and bidding is up to 35k now.
Accounting for the differences in the mod and Q, I'd say start bidding at 15k at least, and see where it goes from there.
Here's the link to the auction I referred to:
http://www.guildwarsguru.com/forum/l...light=stormbow