Rain bow

The Rain bow is a members-only Old School RuneScape item — “Short but effective and very colourful.”. Its Grand Exchange buy limit is 18,000 per 4 hours. Right now it buys at 60,000 gp and sells at 94,023 gp — a net margin of 32,143 gp (53.6% ROI) after the 2% Grand Exchange tax of 1,880 gp. High alchemy yields 300 gp.

To flip it, place a buy offer near 60,000 gp and a sell offer near 94,023 gp; the spread minus GE tax is your profit. Confidence figures are model estimates from live OSRS Wiki prices, not guarantees — flip responsibly.