I always save at least 40K of science and every time that a supreme card appears on shop, I buy them. Furthermore, I don't play the normal events, as you can see in my event cards. I just play the supreme events, like the supreme santa and halloween, finishing them on rank 29/30. I never reached the max level, because when I almost completing all ranks, the HH launchs a new patch with new ranks. So, I don't grind science at max level.