Rune longsword

Rune Longsword is a free-to-play item on the OSRS Grand Exchange in the weapons category.

In-game examine text: "A razor sharp longsword."

It has a Grand Exchange buy limit of 70 every four hours, a high alchemy value of 19.2k gp, and item ID 1303.

View on OSRS Wiki

Rune Longsword shows an active flip setup with a margin of +7 gp and 47,002 trades over the last 24 hours.

At the buy limit of 70 every four hours, max profit per cycle is about 490 gp — high margin with healthy liquidity.