You price yourself according to the work and the resources you need, and the level of help you provide.
Examples: by the transaction, by the Task, by the Hour. Or, as a Contract fee.
If you have to own a computer and Desktop QB, that is part of your own overhead for being in business.
For instance, I started out with Hourly, and have one client under Monthly Contract that I first computed as roughly $5 per transaction projected for sales and payment of expenses.
By Task = running payroll each time, doing reporting; Banking reconciliation.
You have resources on the web for Market Rates in your region for service providers, as well.
Google this phrase:
intuit rate survey 2018