First, I love how easy and simple this plugin is. I'm confused about the difference between pro paying the extra $19 a month vs not. It's not possible for the web owner to export a print ready file?

Is there any option to simply save the image the user uploads for the owner to print?

How can I test the demo of pro vs regular? 

To get print-ready files you must get the pro extension because in the basics export, you will not get a print-ready file.