Board Thread:Game Discussions/@comment-203.30.93.14-20140307055519/@comment-198.160.9.62-20140307151450

I used mostly free gems to upgrade all mine. I figure it's a better investment than opening a 30 gem special chance chest for another 2* armor. At least I get to look at my pretty training grounds and get the much higher gold income.

Level 2 Training Ground: 1200 gold/hour - max 16,500

Level 3 Training Ground: 1800 gold/hour - max 24,000

2 level 3 training grounds generate as much gold as 3 level 2 training grounds. Over time, that really adds up.