How to flip Zamorak brew(4) in OSRS

Flipping Zamorak brew(4) on the Old School RuneScape Grand Exchange currently makes about 152 gp profit per item after the 2% GE tax: buy near 505 gp (the instant-sell price) and re-list near 670 gp (the instant-buy price).

• Buy at (instant-sell): 505 gp
• Sell at (instant-buy): 670 gp
• Margin after 2% tax: 152 gp (30.10% ROI)
• Buy limit per 4 hours: 2,000
• 24h volume: 24,560 (very liquid)
• Max profit per limit cycle: 304,000 gp on 1,010,000 gp of capital

The flip, step by step

1. Place a buy offer at or just above 505 gp (the current instant-sell price).
2. Wait for the fill. Zamorak brew(4) is very liquid right now, so offers usually fill within minutes to a quarter hour.
3. Re-list at or just below 670 gp (the current instant-buy price).
4. The GE takes 13 gp tax (2%) per item when it sells, leaving 152 gp profit each.
5. Repeat up to the buy limit (2,000 per 4 hours), a full cycle is 304,000 gp on 1,010,000 gp of capital.

Margins move constantly. Re-check the live Zamorak brew(4) numbers and price chart on GrandExchange.com right before committing.