Guild Wars 2

I’ve been gearing my Mesmer so far but these runes are really expensive, farming pieces to get the runes of thorn for my necromancer was nowhere near this, so I’m wondering if I really need these 30% Boon Duration or I can go with Durability runes instead?

You don’t need them, the extra boon duration from them allows you to use less commanders gear and/or less exotic trinkets with platinum doubloons, which increases your personal DPS. In the end you staying alive and keeping quickness/alacrity up is more important than the 2-5k extra DPS runes of leadership would allow you to get.

The goal is to reach 100% boon duration in the end. You don’t have to use leadership runes.

You can definitely use durability runes and a few more commander gear to make up the difference. But remember with the amount of toughness you get, you might just want to play the tank role in raid.

Watch Mighty Teapot’s Minstrel Mesmer build video and use Monk Runes instead.
http://metabattle.com/wiki/Build:Mesmer_-_Cleric/Minstrel_Tank