I think you can fill 100 dollars..I had 2 requests and one appeal...and each time they waived and was not charged.
Most requests are not that difficult i guess hence they dont charge. I dont know their criteria for fee assessment but here is what the website say.
Note on website:
"In the event that fees are incurred beyond what you are entitled to for free, please indicate a specific amount that you are willing to pay. If you do not indicate another amount in FOIAonline, please be advised that some agency regulations provide that making a FOIA request represents an agreement to pay fees up to $25 (See agency specific regulations from the links on the main page). "
