It's really, really early on a Monday morning as I write this: "zero dark-thirty". Some ideas just refuse to allow sleep until you share them. So, while shivering in the pre-dawn cold, I offer the following for your consideration...
Picture if you will, just for a moment, the idea that your enterprise applications system is like an iceberg. There are the system costs that you can see. Then there are the costs below the water line, those that you can't quite see. Well, at least those nobody talks about when selling you an enterprise system.
Hanging with the iceberg simile, this is your IT system:
This is your enterprise applications system on SaaS: