1. WRITING
Interviews, transcriptions, and first and second drafts:
6 x 2-hour interviews @ $60 per interview (12 x $60) = $720
12 x 2 hours transcribing @ $60 per hour (24 x $60) = $1440

Writing time is difficult to quote but if an average one hour interview is 7000 words
7000 words x 12 hours of interviews = 84,000 words
I write approximately 800 words per hour
84,000 words divided by 800 = 105 hours
105 x $60 per hour = $6300   

First draft (including interviews, transcriptions and writing)
$6300 + $720 + $1440 = $8460
Second draft: 40 hours x $60 = $2400
Total number of hours = 181
181 x 60 = $10,860

TOTAL FOR WRITING: $10,860
2. EDITING: $3000-$5000
3. PROOFREADING: $2000-$3000
4. CREATING A BOOK: Typesetting, layout, cover design, printing (depending on how many books printed): $3000-$5000
TOTAL COST: $17,000 - $24,000
NB: This is an estimate - the cost will vary depending on the size of the project.