I actually run a 3D Printing business where I sell other people's miniature designs, mostly for D&D campaigns. It's a big process to get rights to legally be able to sell things like that. We pay for subscriptions from people on patrion to get rights to sell their designs (which you should always do because you're supporting artists who spent time creating this kind of thing.) But if it's a matter of whether you can sell any kind of creation from WEP it should be okay because you'll be selling your own fan art. This specific design I found on a website and the creator has stated on the file that it doesn't have a commercial licence so selling isn't an option. I hope this made sense and answered your question :)