Rune essence

Rune Essence is a free-to-play item on the OSRS Grand Exchange in the runes category.

In-game examine text: "An unimbued rune."

It has a Grand Exchange buy limit of 20,000 every four hours, a high alchemy value of 2 gp, and item ID 1436.

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Rune Essence currently has a flip margin of −1 gp, which isn't profitable to flip right now despite 483,766 trades over the last 24 hours.

Items with negative or zero margins like this are better watched than actively flipped until the spread widens.