I start every estimate with a word count and then multiply it by one US dollar. A full-size volume runs about eighty thousand words. Twenty might be enough for your story, especially if you have lots of images. This cost includes one or two sections of photos embedded in the pages. A coffee-table format, with in-line images and sidebars, is more complex and costs more. All this is settled in advance.
To save time (and money) you might reduce the number of revision cycles, but a polished story that draws the reader in takes more than one or two drafts. A good book gestates. It needs time. Writing a life is both surprising and wonderful in equal measure. If you’re willing to commit to the process and truly curious about where it leads, drop me a line.