Cost of using Roku?

How much does it cost to operate a Roku device?
Are the Ultras due for an Upgrade soon?

I have multiple Roku (standalone) devices and the cost was the one to buy it. There was never a charge to use it UNLESS you want to subscribe to paid programming.

I seem to remember that there may be a credit card used to set them up in the event I want to pay for paid programming. I have never done that and never updated the credit card (if it asked for one).

The same here. My only costs have been what I paid for the devices.

I have never been asked to enter any payment information in my account I know you can do it if you want.