Solo hunting is like Zdzisiu wielki said, you need 800-1k arrows for long hunts.
On team hunts or duo hunts you don't use as many, because you kill faster the pulls. I normally begin a hunt of 2h with 600 arrows when I go duo hunt and they last me until the end.
Some tips I would give is not to use them when there are not Many creatures or while luring; at those moments use Aoe runes and mas san. Also try to target a creature which is in the centre of the others if you are running while killing; and if you are blocking a 9 box or hunting with an ek, target the creatures which are horizontal or vertical to him, so the hit of the Diamond Arrow will do damage to all the creatures on your or his diagonals.