Proboscis

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

In-game examine text: "A giant mosquito's proboscis, aerodynamic and sharp!"

It has a Grand Exchange buy limit of 100 every four hours, a high alchemy value of 3 gp, and item ID 6319.

View on OSRS Wiki

Proboscis shows an active flip setup with a margin of +85 gp and 4,763 trades over the last 24 hours.

At the buy limit of 100 every four hours, max profit per cycle is about 8.5k gp — high margin with healthy liquidity.