If you are just starting out online, I strongly suggest that you do NOT outsource your ebook.
To become successful, you want people to get to know YOU and only YOU can make that possible.
Having someone else write the ebook for you, will not convey you, your writing style or technique
and YOUR passion for the subject matter will NOT shine through.
As for the length of the ebook, or the time it takes, well, that all depends on you. I could write a
6 page ebook in 19 hours whereas you may be able to create a 312 page ebook in 6. (No, it don't
take me that long, I am just saying...)
Many factors come into play when writing ANY ebook...
- Whether or not you are passionate about what you're writing about
- Whether or not you actually KNOW what you're writing about
(the less research you have to do, the less time it will take)
- How fast you can type (or speak if using some sort of dictation software)
- How long you want the ebook to be
- How much content you want to provide
- How intense you want it to be
- How "explicit" (and informative or descriptive) you want to be
As a few have already said, no one can determine how much time and ebook SHOULD take to write.