In terms of legality, i don't think you are allowed to do that. If you are using for example; Yung Bae's logo on an otherwise black shirt, it wouldn't be legal. Because you don't own the rights to use that logo. If you made your own logo, then maybe, but if you use the already copyrighted logo then you are infringing on the artist's right to distribute their own merchandise. i.e the black shirt with the logo, so in all technicality you are breaking the law. I don't think for personal use argument really works here either, as there is a company printing it and therefore it would be distribution of copyrighted material by said company.
Though would anyone know if you got sent a t-shirt with the logo of an obscure artist, from a factory far away, probably not. Would the printing company know; idk how thorough they are, but probably not.
Personally i know i would like to do it. Though with the scene as relatively small as it is I'd rather wait, pay a bit more and have the money go to the artists themselves.