There are some really useful FOIA requests - "just because" is not one of them.
It seems that Smartprocure (
http://smartprocure.us/understand-smartprocure/) is trying to build a central database to help businesses - relying on FOIA requests and then reselling the data to businesses. It might be they are reaching out to all public libraries in the state - just on a fishing expedition.
This is the information on FOIA from the University of Michigan -
http://foia.vpcomm.umich.edu/ All requests have a more finite structure and scope. Everything over the last five years seems a bit much - especially if it is someone outside the state (they are from Florida). However, they might be working with a Michigan customer.
The Library of Michigan has a nice resource page for trustee info which might be useful:
Michigan Library Association had a workshop on this in April. Maybe people who went can chime in. Sounds like a good topic for future MLA sessions.
I have seen some expensive charges from governmental entities - sometimes excessively high - for FOIA requests. I do not encourage people to come up with high fees - just what is covered to reasonably do the work. I would let them know what it will cost and what they are looking at.
And when they say...why are you charging so much - you can talk about the effort involved in this work - or simply say.... we are charging this "just because".
Best - Corey