True, the ideal strategy would be to grow the herbs that give the most profit (currently Rannars), sell the herbs, and buy the most cost effective ingredients for herblore (currently, incidentally, also prayer potions.) Actually... Zamorak Brews are currently the best overall. Seeing as he's only 71 herb, though, prayer pots are still the best. http://runescape.wikia.com/wiki/Calculators/Potions I saw and ignored that for two reasons: 1. He can't make them. 2. I can't imagine a large market for Zamorak Brews. You wouldn't want to get stuck with 10k unsellable potions.