Fraction of the cost? Really? That’s less than a single junior dev fully loaded. Laughable you would even consider this at $2B revenue.
"...internally developed and maintained for a fraction of that cost over the products lifecycle."
Now, imagining a lifecycle of this specific app in question of 5 years, are you suggesting that a total spend of $900k for the SaaS would be LESS than developing and maintaining this one tool internally?