I'm at the point where the witch's upgrades cost more than one million lollipops. It's a pretty big grind to get that much, as the max is 300/second. Roughly 55 minutes is how long it takes, although if I want to I can turn my candies into lollipops and make the production 348/second, but that's marginal and at this point candies are more valuable than lollipops.