Well even if they were interested in selling it, you would not make any money off it. If you look at the EULA for the Creation Kit, any mod created becomes the property of Bethseda - at least in the USA as I'm not clear on exactly how European courts would react to the EULA. Anyway, what the EULA says is:
If You distribute or otherwise make available New Materials [Mods], You automatically grant to Bethesda Softworks the irrevocable, perpetual, royalty free, sublicensable right and license under all applicable copyrights and intellectual property rights laws to use, reproduce, modify, adapt, perform, display, distribute and otherwise exploit and/or dispose of the New Materials (or any part of the New Materials) in any way Bethesda...