That's a really tough one because you don't know how to clean residential. Just an example, on a first time clean, if the shower is really dirty (build up soap scum and mold in all the grout) how long would it take you to clean it? I'm sure atleast twice as long as me or else you probably wouldn't get it as clean as I would. I could clean it faster because I've done thousands of them. Just like with your normal commercial work... it would take me 4x as long to strip and wax a floor because I never do it.
You wouldn't have a normal routine..... you wouldn't really even know what all you would clean. I say that because all new people clean way more things than they should and take much longer to do it.
But I guess to get an answer so you can give a price.... probably not going to be correct.... how many man hours do you think it would take you to clean it?