Okay; I counsel business people, so I will take this one:

"In turn I will pass on to them the filing fees, but no other charges on my part."

You just completely devalued yourself and your professionalism to them.

You are being asked to provide something of value to them, that also costs you.

What about your programs, your computer equipment and your connection costs? You are putting your own E&O at risk, as well. All of this has some value to be recaptured. It's one thing not to charge your usual rate, or have the intent not to profit, or be willing to work for free. It's another to be paying for all of the infrastructure you are providing to them. Otherwise, why don't they do all of it in house and without you? The answer is, they find some value in your involvement. That is either Nefarious or Innocent, but not Free to you. Why should it be free to them?

Here's one example: I own and update more than one computer, so that if something dies in the middle of the time I need it, I move over to the other one. That costs me time and money to have a "spare" on hand that is ready to go, and as a professional, I am willing to invest in that provision.