Talk:Archangel's Staff/@comment-4636093-20120604083546/@comment-186.213.149.55-20120606034651

The formula is "(((577 - 80x - 5y) * 500) / 3z) - 1500", where: Typically, it's said that it costs 20 gold per AP, 2 gold per mana and 55.71 gold per mp/5, so solving the formula says that you need " -346.25 " mana to the item become cost efficient (that is, the item is always cost efficienty, even if you had some negative mana, reducing your total AP).
 * x = How much every point of mana is worth.
 * y = How much every point of mana regeneration is worth.
 * z = How much every point of AP is worth.

REALISTICALLY SPEAKING, late game mana and mp/5 are devaluated, so you shouldn't factore in the gold gains of mana and mp/5. If you want this item solery for AP, the formula says you need " 3308.33... " mana points to break even (that's it, you spend your gold better stacking Large Rods until you have 3308.33 mana, from which stacking Archangels will become more and more cost-effective the more mana you have).

The "3308.33..." manapool figure is literal: It includes both the champions base pool and the mana given by the Archangels, as opposed to "bonus mana points required". If you have "3309" maximum mana showing on your hud, you know Archangels are cost efficient, as is.