Talk:Gold Mine/@comment-6617823-20130220195330/@comment-99.239.233.150-20130417225020

A lot of this math can be simplified substantially, all you need to do is calculate the amount of resources you missed (upgrade time times production rate), and calculate the time it would take to the new extractor to generate that amount on top of the original rate (divide the missed resources by the difference between the two rates to get the time it will take to break even, add the build cost to the missed resources if you must) and that’s it for example:

lvl 10 to lvl 11

original rate: 2500

new rate: 3000

upgrade time: 5d or 120h

missed resources: 2500 * 120 = 300000

time to break even: 300000 / (3000 - 2500) = 600h or 25d

(note this example does not account for build cost)