Lobster

Lobster is a free-to-play item on the OSRS Grand Exchange in the food category.

In-game examine text: "This looks tricky to eat."

It has a Grand Exchange buy limit of 6,000 every four hours, a high alchemy value of 42 gp, and item ID 379.

View on OSRS Wiki

Lobster shows an active flip setup with a margin of +1 gp and 417,884 trades over the last 24 hours.

At the buy limit of 6,000 every four hours, max profit per cycle is about 6.0k gp — high margin with healthy liquidity.