Compost

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

In-game examine text: "Good for plants, helps them grow."

It has a Grand Exchange buy limit of 2,000 every four hours, a high alchemy value of 12 gp, and item ID 6032.

View on OSRS Wiki

Compost shows an active flip setup with a margin of +2 gp and 48,174 trades over the last 24 hours.

At the buy limit of 2,000 every four hours, max profit per cycle is about 4.0k gp — high margin with healthy liquidity.