This depends on how much Eternal Earths and Shadows go for on your server and also how much Infinite Dust and Greater Cosmic Essence. Also a little bit of luck.
All you need to do is make Shadowmight Ring (link) and Disenchant it.
The ring takes 1 Eternal Shadow and 1 Eternal Earth.
Go to the AH and depending on your servers economy Earths and Shadows are 6g each on my server, and as long as I hit 4 dust from DEing, I break ever/ little profit.
So check out the prices, do a little math, buy in bulk for best result.
Edit: Forgot about "Stoneguard Band", they take 2x Eternal Earths.