Go the the mystic forge and put in -
1 x Master's Salvage Kit
1 x Journeyman's Salvage kit
1 x Fine Salvage kit
3 x Mystic Forge Stone
You will get 1 stack of 250 Mystic Salvage kit.
(Use karma to buy the ordinary salvage kits if you want to save even more money.)
(Also, they will prolly nerf the karma shit soon so better do it quick.)
Good luck.