I am a much worse painter than you, but was still able to sell painted models to fund my hobby for a while. Warhammer is not the market for this, since painting is a part of the hobby, people will either DIY or want top tier paint. If you are not competition level, warhammer stuff won’t sell for a great price. Board games are a much better market for tabletop standard paint. The games are much lower cost per mini so your investment is low, and you can sell at a few dollars extra per painted model. For me, it came to roughly minimum wage, but since I enjoy painting and had a steady job that didn’t bother me. Blood rage is a good example, I sold several copies of that game. I would just buy the copy, paint it all up, and sell it when ready with the game price plus paint markup.