The fee called small may be attached to a need someone cannot decline.

A charge is only small relative to something. Attached to an optional purchase it is trivial; attached to a document you must have, a prescription you cannot skip, or an account you are required to hold, it stops being a price and becomes a toll. The people who set it usually judge it against their own budget, where it genuinely is minor. That is how a fee can be modest and coercive at the same time.

If you set prices or policies, ask who cannot walk away. Then look again at whether the amount is small for them, rather than for you.