Teak plank

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

In-game examine text: "A plank of fine teak."

It has a Grand Exchange buy limit of 13,000 every four hours, a high alchemy value of 300 gp, and item ID 8780.

View on OSRS Wiki

Teak Plank shows an active flip setup with a margin of +6 gp and 1,658,328 trades over the last 24 hours.

At the buy limit of 13,000 every four hours, max profit per cycle is about 78.0k gp — high margin with healthy liquidity.