I consider myself a heavy destiny player with nearly 1900 hours clocked from day one. I have had 5 characters in total, all reaching the max level cap at the time. I love re-rolling weapons and try and get the best roll on all my weapons, mainly for pvp as Vault of Glass weapons are pretty much unbeatable for PVE. When HoW came out I had 1500 weapon parts and now I have about 50 - rerolling is becoming more and more difficult and gaining weapons parts is a long laborious grind. In short bungie need to add weapon parts to the crucible and vanguard vendors that sell other materials.