This is my mindset. I am a beginner. I am improving and working on my swing. If I get fit now, the "fit" will be for my current swing. As I continue to (hopefully) improve, the "fit" will not longer be correct.
To play a bit of devils advocate, if you "improve" your swing, is it possible or even likely that the swing you've created, is compensating for some issue that didn't have to exist in the first place? At this point, you've trained your body to make a swing that works, but not the swing that you could have developed with properly fitting clubs.
I truly believe that every golfer would benefit from a proper fitting. I'd argue the most important time to get one is when first starting out, so that you don't ingrain any bad habits compensating for poorly fitting clubs.