Poletax gives one eye of newt, vial of water and grimy guam as free samples. They are the ingredients of attack potion. However, the grimy guam respawns at a much slower rate than the other two ingredients. He also buys potions in apparently unlimited quantities, even if noted. The interface allows selling 50 per click. He will offer the sold potions in his shop for a short time at a steep markup. See Poletax's Herblore Shop for prices.