Having the license drive the max sales price is a little tricky. I can't tell what you would be allowed to do if you sold them (fully or partially) populated and assembled with the right chips and components.
I think it's very clear what you'd need to do - contact the creator and ask for a license.
That might be the right answer if the creator seemed confident about IP ownership and/or was specifically showing a path to paid licenses. It's a sort of "morals clause".