Rate depends on the entity, sole prop, S Corp or partnership, if they need payroll and/or sales tax returns prepared, 1099s. Fee also depends on the number of bank, credit card, loan, PayPal, and Venmo accounts. We have fixed fee monthly agreements which are customised to what the client needs.
I'm and EA, took accounting courses in college and worked for over a decade for a CPA firm. Some of my clients have a bookkeeper who has no accounting background or, at most, a pro-advisor certificate. I do review these books because the owner of the business wants a second set of eyes. One time I found a $145,000 mistake. Bookkeeper didn't know the difference between cash and accrual basis ...
You may have a background in accounting, I don't know. If you have one, good for you and you should be able to build your knowledge into your fee. Because of bookkeeping software, people mistakenly believe bookkeeping is easy.