I'm ranked in the 20s and claiming about 550k every 4 hrs after being attacked a few times just for your reference. The main issue is the continued changes to the chest costs. The top players in the beginning were getting chests at 50x the current rate which allowed them to produce so many land assets and ori that it has hindered anyone from being able to catch up at this point. The denar you buy doesn't go as far as you think....

Good luck!