Lightning bow will probably go for a 1-2k I would guess, maybe a little less even. +15% while hexed is one of the weakest damage mods, it really barely counts in most people's minds. So you're pretty much selling a max damage bow with some average mods on it.
Spike axe will probably go for 1k at best. Chances are you'll end up selling this to a vendor.
Water staff will probably fetch a couple thousand if you can find a water wizard who needs one. Water magic is the least used of elementalist spells, so it could take awhile.
Vampiric shortbow you will probably have a hard time selling. A 2/-1 vampiric mod is not very desirable, and the 12% below 50% is not significant.
Sundering composite bow is pretty good. 5-10k probably. Maybe more, I don't know, never played a ranger.
Sundering longbow probably 2-3k.
Frost artifact is hard to judge, different people look for different things in offhands. Since it is a water req, it will probably sit in storage for a long time.
Buckler is worth probably 1-2.5k.
Hope that helps,
Rico
PC: Bows, Axes and mor
Rico Carridan