Selling non textured models

Of course you can do that. But why should a " Skilled in Texture Artist, Adobe Photoshop, Substance Painter, Mari, and finding inside substance designer. " as you write about yourself do that ??? - With your history and experience that just doesn't make sense!

Yea I do that all the time especially for model that will be kitbashed into something else. Like for a table asset I will texture/shade it but for windows I will leave them untextured, since windows will probably be integrated to an existing wall.