Also, an internal toolkit may look great at the "internal" stage, but become a mess once you try to package it into a product. I've seen and made lots of these

Also, an internal toolkit may look great at the "internal" stage, but become a mess once you try to package it into a product. I've seen and made lots of these for ERPs and stock ops, but every time I thought about making it at least an internal product, it failed. Two reasons: 1) making a product is 10..50x harder than making a solution; 2) extracting your knowledge into an easily consumable form is almost as hard as training a user to replace yourself. Even if you finish it, it will cost much more than just a hire. And the world doesn't have issues with hires atm.