Preparations for a script (development of characters, plot, research, and such.) depends on the complexity of the work, a short comic can be done in one day (unless I need to research complex subjects or long historical data I'm not familiar with), longer works may take months.
Writing a single page may take a minute or two, and a couple more to revise it and make changes if needed, but that's because I know beforehand everything that's going to happen in each page, I have it all written by then (though unexpected changes may happen), I don't start a script before the story is complete.
Then it goes to Eli Navarro, he's a busy man, works all day and has a family to take care of, so he's short of time, but even so he's very fast, I don't know how he does it, he can handle a very detailed page in one day day from pencils to colors easily.
If I'm lettering, then the pages come back to me and it may take me anything between a few minutes to a couple of hours to letter each page.