I only picked up enchanting for Disenchanting quest items for extra gold.
I realized whenever I'm running heroics or 10/25 man I can usually bring in about 100-300g each run.
In 25 man nax I would intentinally put on shitty epic gears and roll on *UPGRADE* I have t7.5 in my bags but I don't care lol.
What ever I get as an *upgrade* i would DE it and voila Abyss Crystal.
I usually get about 3-5 a run depends on my luck. People will forget what kind of gears you got last week when nax reset so don't be afraid to say you need it for an upgrade.
Common Sense? It is, yes, but o well just trying to help those that doesn't have any =)