He cocked his head. "I thought I was being transparent earlier. It's nigh impossible to get an accurate number with all the daily going-ons. Fights, occasional invasions and such." Mason raised his forearm and tapped a few times on the face of his wristwatch. A holographic interface appeared before him, holding up statistics and inquiries. "Let's see here. Altogether, American cleaning companies on Earth in 2015 had business revenues reaching up to $51 billion. So let's start at a flat fee of half that price for cleaning. Then if you feel that you want more of what I'm offering, give the other half of the price. From there, it'll just be fees proportionate to our work's prices."