Talk:Elixir Collector/@comment-14.147.91.4-20130106142216/@comment-82.28.198.195-20130220011406

I would have thought it would be

Cost of the upgrade + how much production you will loose during the upgrade (hourly rate of production x how ever many hours the update takes)

---

the difference in production rate from the lower level to the upgraded level

that will give you an estimate of how many hours until the upgrade cost if covered

E.G.  to go from level 10 to lvl 11 gold

168,000 + 300,000 (2,500x24x5)

--                = 936 hours = 39 days until profitability

500