Marrentill

Marrentill is a members-only item on the OSRS Grand Exchange in the other category.

In-game examine text: "A herb used in poison cures."

It has a Grand Exchange buy limit of 13,000 every four hours, a high alchemy value of 3 gp, and item ID 251.

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Marrentill shows an active flip setup with a margin of +22 gp and 91,744 trades over the last 24 hours.

At the buy limit of 13,000 every four hours, max profit per cycle is about 286.0k gp — high margin with healthy liquidity.