I want to suggest that you add more rune essence to the general store. Reason being, it gets bought out too easily. If with three players it gets bought out you will have a major issue later in the future.
Also, think about it from this point of view...it's the weekend perfect time to get 4x xp by voting well no voting as no essence to train runecrafting with. Just food for thought.
Before you say "you can mine it" that option is obviously there for the irons let them have fun doing that