Been there with a 33M cost estimate [1]. If the requester is reading this -- hold them to it and request a much smaller but still significant amount of records. Use that as the foundation for "how much time it actually takes". Another option is to get clever with helping them with means and modes of review/redaction. This is how I got the email metadata for 6M emails from Houston for example.
FOIA requests that have to be redacted are labor intensive.
However, flock shouldn’t need to be redacted right? They’re just public webcams. Lots of those already exist and many stream live.
All digital government records should already be freely distributed. This is basically the same thing as poll extortion tax. You want to use your rights? Then pay up! Oh you didn't go away yet? Pay up even more!
Another example from Vermont's governor's office: https://www.muckrock.com/foi/vermont-80/email-metadata-55744...
Happy to help more but I'll probably be unavailable tonight.
[1] https://mchap.io/that-time-the-city-of-seattle-accidentally-...
Unless... no, that couldn't have been a lie, could it? The government would never try to overcharge anyone, right?