The majority of the profit from making runes out of rune essence is the fact that at the right levels you can make more money selling multiplied rune making from one essence, but the only runes you can make with regular essence is the cheap ones.
I'd figure regular essence to be around 80-100 each.
Now pure essence, even though right now only two additional runes can be crafted beyond regular essence and you can further sell them at decent prices due to demand and the hassles to make them the essence for them would certainly be worth more.
Pure essence may go from 140 to 180 each.
Thirty mining level helps.