So there was this guide around that said I should farm Cat's Eye Diamonds for selling in Auctions to make money in my 30s range.

That guide was a year ago and I'm wondering if this is still viable?

lvl 40 (white and green) and 50 (green) mining is sold for alot cause people need that to make gems for in their equipment.
I think lvl 30 farming/mining isnt that profitable anymore but not 100% sure (depends on the selling price in auction)

A good and easy way to make gold at lvl 30+ is to sell lvl 30 racial crafting materials guide for it here.

Thank you so much!