My bid is based on your 3 hours/day, which is 15 hours/week or at least 60 hours/month at a rate of $30/hour. (Your stated maximum of $300/month to start equates to $5/hour, or well below the minimum wage.)
I've worked with a wide range of authors, all the way from idea to published manuscript, and in all stages of the manuscript creation, publishing, and marketing. My wife still works primarily in book marketing, while I've primarily focused on copy creation and manuscript development, both in editing and ghostwriting, the last few years.
Please don't hesitate to reach out so we can talk more; I'm happy to share samples of previous work and answer any questions you may have. Thanks much for your consideration, and I hope to talk more soon!