So when you identify a piece of gear there's a low chance it will roll to the higher tier. I just noticed the other day that i never get ectos from salvaging unidentified green gear and that doesn't make sense. I generally get one ecto per yellow on average. And i usually do a stack of 250 greens at once when i do, so i should normally be seeing at least a few if those greens roll yellows.
Also come to think of it i've never got a glob of dark matter from salvaging an unidentified yellow either.
How does salvaging work in the presence of the ability for a piece of gear to roll a higher tier?