Thanks guys. Yes, I had already concluded this and won't be offering the STL file. It will only be available as a finished figure complete with the custom packaging.
This brings me onto another point. Do you think I should go to the expense of having the articulation added (which could also break up the nice clean lines and accurate detailing that the artist has done)? Especially at the red trunks line - it's not possible to get Star Wars figure style articulation to the legs without cutting right through the line of the trunks. I'm thinking that if it's put into the package and sealed onto the card with the bubble, it might not need any articulation, but I worry that it then just becomes a mini statue / Eagle Moss style of statue. Visually, it will look great on the card though.