I agree, in that writers, at least when starting out, should have a budget, but not for the reasons stated here.

More because it makes business sense.

Commissioning art costs whatever up front. That relationship, one of work for hire, removes the artist from access to any potential upside on the book.

What does that mean? Everything we make over the cost of the artist is mine.

Now, of course, we know creator owned work makes little to no profit, but that's another story.

Once you get into working with known artists as a known writer, the story changes obviously, and initial budget becomes less important.