AT the risk of sounding like I'm talking down to you, I have to say: nothing in the system will replace what a lesser quality cartridge did not retrieve from the LP. The closer a piece of gear is to the source the more it will affect the sound since the rest of the system magnifies what took place earlier, while adding it's own signature.
Start at the source and work your way to the speakers. This will result in the most satisfying musical experience.