look up the ingredients and requirements to make a carapace ring.. secondary check of goldsmithing. costed me roughly 600k to get bone up to 60, now imagine doing that for goldsmithing as well :) base material cost also plays a part.
I bought 2 of these for 9k each on Valefor I then turned around and sold my carpice rings for 40k each. I love it when I get better gear and make money doing it.