Monkey bones

Monkey Bones is a free-to-play item on the OSRS Grand Exchange in the other category.

In-game examine text: "These are small monkey bones."

It has a Grand Exchange buy limit of 3,000 every four hours, a high alchemy value of 1 gp, and item ID 3183.

View on OSRS Wiki

Monkey Bones shows an active flip setup with a margin of +251 gp and 825 trades over the last 24 hours.

At the buy limit of 3,000 every four hours, max profit per cycle is about 753.0k gp — high margin with healthy liquidity.