I stopped aggressively farming at 1300% and I stopped buying mystery boxes to raise my multiplier as well.
At 1300, I do 24 KEM's every four hours to keep a steady daily flow of donuts-- I can buy every premium item released in events/sales etc and in the lull between my donuts rebuild easily. With the rest of my cash I'm working on Cecill's "Rock and a Hard Place"-- 1M each 4 hours.
With that arrangement, my cash level isnt' moving (isn't going up but isn't going down either)- my donut level does roughly the same (goes up between premium item releases, enough to pay for everything, and then start over) -and other than the 24 KEM's (cause they're dirt cheap) there's no farming going on. It's a nice nice change from the amount of work that went into bringing the multiplier up. I couldn't imagine continuing that for months on to get to 10k % ! But - I don't really need to.
