User blog comment:Milesprower2/PvZ Math: Cost Effective Attackers/@comment-4077536-20141122121417/@comment-4077536-20141122161926

Since I have no idea how to write formulas in wiki text, I typed it in word and took a screenshot. Now, this formula would need to be adjusted for plants like Bowling Bulb, and it kind of breaks when it comes to single zombie plants, but it's a start.