Big bones

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

In-game examine text: "Ew it's a pile of bones."

It has a Grand Exchange buy limit of 3,000 every four hours, a high alchemy value of 1 gp, and item ID 532.

View on OSRS Wiki

Big Bones shows an active flip setup with a margin of +7 gp and 346,065 trades over the last 24 hours.

At the buy limit of 3,000 every four hours, max profit per cycle is about 21.0k gp — high margin with healthy liquidity.