Talk:Gold Mine/@comment-5631351-20130104090638/@comment-5687967-20130212225308

Once again, the mine doesn't produce while it is being upgraded.

That means if you upgrade from Level 9 to Level 10 you miss out on 4x24x2200 = 211,200g. Yes you make 100,000 gold in 40 hours after the upgrade is complete, but if you hadn't upgraded you would've made 88,000g with the level 9 mine. This is a difference of 12,000g. That still leaves you with a 199,200g loss.

The elixir you paid to upgrade the mine is lost forever.