For an upcoming short film, I was going to shoot on my iPhone 8, which has a 4k camera, and is good for quite a few feels for the movie and look and stuff, but I recently started thinking maybe a more professional video camera would be better. There are problems with phone cameras, like variable frame rate, small aperture, and not the best low-light (although I don't need any low-light, just a thing to consider).
Should I go for a nice video camera? It needs to be at least 4k but other than that I'm not sure what I need in terms of technical schematics. Also, I can't go over $300. I could stretch it a tiny bit but that's pushing it... and I was thinking of buying used to save costs. Getting a professional video camera could make my movie look better, but is it worth it?