It is possible to sell Scratch projects, as long as they are not shared on the Scratch Website. The creator can attach any license they wish to the code. However, once a project is shared, it is automatically released under the Creative Commons CC-BY-SA 2.0 license, which allows anyone else to view or remix it free of charge. This means that you will need to have never shared your project to Scratch if you are planning on selling your project, since the Creative Commons License can never be canceled. Selling copies of the Scratch program itself is not allowed.
This forum topic contains more information on the subject.
- "Can I sell my Scratch projects? — Yes: Your Scratch project is your creation." scratch:faq