I think "buy the best you can afford" advice is good for ANY artistic endeavor; but "what you can afford" is a bigger statement than it looks like. I decided I couldn't afford a big sewing machine at first; then later I decided I NEEDED one and suddenly I could afford it just fine. My income didn't change one bit, but "what I could afford" did because quilting had become more important to me.
I suppose usually I'm buying the best I can get for the task at hand. But 'best' is subjective, too, and the task at hand may or may not need that professional-level touch.
I DO consider myself an artist, but I don't specialize. I explore and enjoy. I have a whole garage full of past obsessions, all of which influence or are incorporated with each new thing I discover.