I’d like to suggest a way to export medium quality .stl with inline payment transaction in free version.
For instance .stl low quality remain for free,but if i need better quality i can export a single medium quality stl paying , for instance, 3 euro.
I think you can do a lot of money with occasional user like me and occasional user may be happy to work with sharp3d.
Not a chance for me to buy the professional version just to create 1 or 2 object at month for my 3d printer. Too expensive for my purpose.
Hope your commercial Office can take this suggestions.