The ideal range of indoor relative humidity depends on the specific objective. It will differ depending on whether the objective is occupant thermal comfort, stability of interior trim and hardwood floors, minimizing the potential for mold/mildew growth, etc. The range I've seen which balances all of the considerations is 30% R.H. to 55% R.H. That said, I would carefully consider whether to increase indoor relative humidity in a cold climate zone due to the potential for condensation to occur in stud cavities. Proceed with caution.

The other argument is "what is it worth to you?"

You never stop paying for a humidifier. (maintenance, repair, replace) Due to the nature of how they operate, the condition of water they are attached to leads to continuous and non stop maintenance, if you don't perform that the unit won't last long (operationally speaking).

There is no warranty for an appliance that is not maintained. So there's that too.

Maintenance doesn't intimidate me. I'm probably in the top 5% of home owners when it comes to caring for their homes. I change my filters every 3 months, I wash using that foam stuff my A-coil and outside unit/fins. I keep yard debris from clogging up my outside unit/fins.

My water is whole home KAC filtered, with a sediment filter and softener. You change the water wick annually, right? Thats it?

Oh and I still call a professional once a year to checkup on everything, charging refrigerant is something outside of my skill set.

If you decide a whole-house humidifier is right for your needs, you'll be better served by a steam humidifier than a bypass type.

In a cold climate such as yours, 40% is a safe number in winter. 50% will often cause condensation not only on windows and doors, but possibly inside walls and other places you don't want moisture.

What temperature do you set the thermostats in the winter? What are you using to measure the humidity level? Do you know the meter's accuracy?

The most important question are you comfortable? If the answer is yes, then you don't need a humidifier and the expense and maintenance it requires.