Board Thread:Dragon City Questions and Answers/@comment-177.229.77.177-20130528231742/@comment-9946604-20130606001243

1815.6 gold per minute with 12 crystals (for +240%), but I doubt you could get that many in range. If you put the demon dragon in a big dark habitat by itself, it would hit the 80k cap every 44 minutes.

This also has nothing to do with 124.6.181.167's comment. They are talking about a known bug. My advice to them is to contact social point.