Having killed Reindeer for hours to complete this quest I can assure you that you are mistaken - or there was some really weird glitch that meant lots of Elder spawned at the same time. And if there was a glitch then you can't really blame a player from PKing to make sure that they benefited from it.
This is one of the Vahtos 'grind' quests, if I am not mistaken. Such as Excellent Boar Meat (my record I think is 149 boars for the three quest items, that is the lowest), Elder Reindeer and Tree Roots of Power from the Ents in Jade Valley. I didn't check my kill meter when I was doing the Ents quest but I remember on my main giving away more that 200 daily quest items when I completed it on my main.
Elder Reindeer are rare. You will have to farm the hostile deer a lot. If you are in a guild or have in-game friends I would recommend making a party and killing together (particularly for protection from PK) as the it will go quicker and it will seem quicker as you will have more fun.
And if you think Elder Reindeer are rare, there is someone even rarer that spawns on the same points - Akeli the Sage. I can guarantee you that only a handful of people have ever even seen Akeli, yet I have seen his card on sale on my server for 500kk.
And PS, I wouldn't tell the likes of Inferiority that he is assuming stuff. Not that I want to say that he knows too much about the game to be actually healthy,
but...
Edit: lol, that was a mild response, Inf