I’m very much in favor of NOT making your book a DIY project. Yes, you can save money that way. But will you end up creating a quality product that your potential readers will value enough to actually purchase? Treat your book like a business, and invest in outsourcing the parts that you’re not an expert in, such as:
These are all people that I know well enough to recommend. They are not affiliate links, and I will not receive a commission if you work with any of these professionals.