On my second account which is level 76 I have gotten over 50,000 coins with 1 day 7 hours left. I have gotten all 3 monsters and just have a few tiles left to start round 2.
On my main account that's 117 I have got 5500 coins and will not get any monsters. I played both accounts about the same amount of time. Probably paid more attention to main account, trying to get as maximize coins.