Value billing here. We do all of it and just wrap it into the final invoice. I gave up billing for individual services decades ago. Too much trouble.
For one select client, I charge the time of our bookkeeper who does it all, at a somewhat discounted rate of $45/hr. (She tracks the time…I don’t need to. Phew.)
I try to encourage clients to get their bookkeeping and payroll done elsewhere, so I don’t have to deal with it. But, for those that really want me to, I charge $75/hr to set everything up (in Sage or QBO or whatever), then $25 per paycheque.
Even if I don’t do the client’s bookkeeping or payroll, I will still do T4s and ROEs as needed - typically $60 per slip. If I need to do 5 or more at a time (and they are all similar), I discount that to about $45 per slip; 10 or more: $30 per slip.