The game is designed for cashers. The bigger issue is the cost of boosters. I complained about the last Maze event. It was 300/3000. This time it is 1000/10000. So, if you collected 25K stars you managed to collect 20 boosters or 25 if you opened 1 at a time. You can't even promote Merida past level 50 at that rate, and you have to have her on your team.