Yesterday i checked prices from Mining materials on my server. And as we all know end-game mats of vanilla (thorium/mithril) are expensive. Now what i also saw is that (on my server atleast) they are worth more then saronite...
Saronite full stack = 20G
Mithril full stack = 50G
Thorium full stack = 70G
Even old gems are going for 15G a piece! some even for 30-50G (I'm looking at you Azerothian diamond!)
While I see hihglvl gems going for the same and even a lesser price!
So my advice for you: Are you lvling mining? or lvling a character? or just a high lvl miner and bored?
Try to go to some old locations with mithril/thorium (every 50-60 area is great! except for feralas) And see how much money you can make..
Ariäni lvld the past week, and while I didn't go out of my way to get anything. I came up with 3 stacks of mithril that I couldn't use anymore, and some stones and lowerlvl gems.
While lvling I made 250G just from those stacks. in a lvl 50ish area...
I don't know if you remember but...250G was a big deal back when on vanilla. Now 250G is enough for a raidnight and thats it, but while lvling this can get you a long way.
So again, if your lvling or want to start it, get mining... It's a pain in the ass from tin to iron (gap is quite big) but after that you'll thank me.