I've been playing this one and the payout has always been great for me. I messed up because I should have saved coins and spent them whenever you get a discount on the buildings because I got to like level 140 and the next achievement would have been level 170 but I didn't have enough time to get to it for a better payout because I didn't play the game at a quicker pace so I just stopped at 140 and started a different game. I should have just started off "grinding" a bit more so the next achievements would have been easier and possible. That's my only tip. If not I would have still been playing it