Only you can know what you need to charge for particular situation. There are many different business models. That being said, most folks that I know of are about $1 to $1.50 for the clean and first grit. An additional .75 to $1 for each additional grit when using diamond pads.
Very helpful
The Revive color enhancer can be helpful, but personally I don't usually like it on marble. (It does look great on the slate floor in my home.) I would suggest a penetrating sealer such as Spinergy SolidRock.
I wonder why my I-link distributor didn't mention this when I was buying the 80.00 dollar per gallon Revive?? Hmmm......
Since you never mentioned the level of shine that you are going after, we can't know what is "like new" condition.
Well, high gloss is how I would put it. I don't remember ever seeing a low gloss marble.
Here is a rule-of-thumb on how to decide on what pads to use. If you can tell the floor is scratched and abraded but can't feel the scratches with your finger tips, consider starting with an 8,000 grit pad. (It is still possible that you need a 3,000, but not likely.) Then go to the 11,000 for the highest gloss level.
If you can feel the scratches but they are minor (not something you could put a fingernail into) then start with the 3,000 grit pad and work your way up.