you can kill green dragons, play Great Orb Project then trade in for Pure Essence, Try your luck at God Wars Dungeon, or do many other things. Experiment. Also you can try your luck in PvP or try the 26k Trick.
You may choose to runecraft in the abyss. Hopefully you are higher than level 82 and have a good def to withstand the hits. Craft laws and if you have 75 rc or higher, you'll earn almost 700k if you have quick mouse reflexes.