Combat potion(4)

The Combat potion(4) is a members-only Old School RuneScape item — “4 doses of combat potion.”. Its Grand Exchange buy limit is 2,000 per 4 hours. Right now it buys at 140 gp and sells at 185 gp — a net margin of 42 gp (30.0% ROI) after the 2% Grand Exchange tax of 3 gp. High alchemy yields 129 gp.

To flip it, place a buy offer near 140 gp and a sell offer near 185 gp; the spread minus GE tax is your profit. Confidence figures are model estimates from live OSRS Wiki prices, not guarantees — flip responsibly.