Why is Efreeti War Bow so expensive?
 

Besides rarity, quest is a 45/60 bow, there are better ratio bows that are cheaper, is it because the 45 damage is the highest damage on a bow? what are the uses? PvP / kiting?

In PvP it's because the proc is an unresistable spinstun which just means death to the target when an assist train hits them. In PvE, it's because it is the only bow in the game with 200 range and a detrimental proc. The way archery works, the arrows you shoot take time to travel to the target so they will not hit instantly, but if you proc on the shot then the proc hits the target instantly. This combination of maximum range and a proc means that a Windstriker can obtain FTE on a raid target instantly from 350 range (using 150 range arrows) when it procs. Nothing else comes close to that.

Is Plane of Sky still a regular thing for guilds?

yes

Has anyone in the history of P99 actually got FTE in this fashion? Serious Q

seen motg and tunare FTE this way, but not with this particular bow, a 180 bow +proc still can beat a 200 with flight time. is it worth the burging out for? no

Yeah I've seen Windstriker procs for FTE before. It's a minor edge in the grand scheme of things, but winning is usually the accumulation of minor edges.

it's kinda a weapon people don't really buy but rather get from being in a raiding guild

I’ll buy one 100k.

Windstriker takes a ranger from a joke to a shotcaller overnight in PvP. All other items come secondary, including Tolan's Longsword, Cloak of Throrns, Dark Cloak of the Sky and Primals.