I had to work with an artist to get this sketch and you know what? It wasn't that expensive. Especially line drawings. I usually like to budget for character sketches for each project. If I just get the main characters usually that's fine. I've spent from $5 on fiverr to $50 on upwork for a sketch of any one character. It helps me and when I think about the characters more and what they look like, they give me a sense of who they are.
Just another trick to beat another form of writer's block. It's also an awesome feeling to get pictures of your character. A one of a kind image of the people inside your brain. For me it's worth the expense.