Hi Duncan. Welcome aboard. It's a pretty deep rabbit hole you've stumbled into - enjoy the journey.
Your inventiveness in selling your pens will evolve over time if you have the motivation to do it. For many, pen turning will always remain a hobby but there are plenty of folks out there who earn a living from it, or at least a good part of their living. There is definitely a market out there for pens if you have the will to pursue it