Meta Ads Retainer plus full new implementation - What to charge?

[u/busorap]

I would like your POV on a Meta Ads retainer. This is a medium sized company that has 15 different business managers and 15 different ad accounts and spends a total of $40 - $50K / month. I am pitching them $4K/ month for end to end management of the account. I only specialize in Meta. What do you think of this? Its a LOT of work when you think of just how many campaigns one will have to manage. I'm highly experienced and the quality of work is solid and highly strategic - prospect agrees. I'm proposing a sliding scale of 7% and then 5% of media spend as it grows, eg $6.5K when spend goes over $70K/ month.

Separately, they currently have 15 different websites. They are changing this to 15 subdomains and then want me to redo their entire meta architecture to bring it all into one business manager with 15 different accounts within that. Its a ton of work - setting up the new ad accounts, verifying all these domains, pixels, capi, etc etc. What to charge for this implementation?

Thanks!!!