I think the NonCommercial clause applies to others, not to the copyright holder. And even then they can sell it if they get permission from the copyright holder. See what I've found here:

CC's NonCommercial (NC) licenses allow rights holders to maximize distribution while maintaining control of the commercialization of their works. If you want to reserve the right to commercialize your work, you may do this by choosing a license with the NC condition. If someone else wants to use your work commercially and you have applied an NC license to your work, they must first get your permission. As the rights holder, you may still sell your own work commercially.