ok first i'm going to share my cheatb it is
Hint: Easy Money and Experience
Complete rune mysteries quest in either free server or member server.
After that you have the ability to go to the rune essence mine so get a pickaxe.
Go to rune essence mine, the Varrock Rune Shop has a bank nearby.
Teleport.
Mine essence till full.
Go to portal.
Go to bank deposit essence.
Repeat. You now have enough essence to sell them 10K= 500 RUNE ESSNECE, 20K= 1K Rune Essence, 30K= 1.5K Rune Essence.
Submitted by Pyromecha