The infinite overload (i) is an end game item it shouldn't be easy to get and you don't even need to focus on just getting it it'll come with time through donation points or vote points or slayer by killing darklords, you've been very unlucky upgrading it i agree that doesn't seem fair but it's the way rng works. Obviously Wolf knows more than us about balance so they can decide the best solution.

Theres a suggestion format posted by Nate using that only helps your suggestion, in my opinion pest control is perfect the way it is you can get the infinite overload many different ways. Vote shop for 7500 voting points Donation shop for 50 points. upgrade 5 limeys and you've got it. Darklord shop for 12 tokens