Cartridge: Disclaimer - I have no recent experience with inexpensive cartridges. But, you fell in love with Miyajima - do they sell an inexpensive one? I have heard and read good things about the Nagaoka line, it is or was the factory recommendation for a good line of turntables. What does your dealer say?
Don’t buy used!!! Except from your dealer or another trusted source. Not until you have more experience.
May I also suggest an inexpensive alignment protractor, and an inexpensive torque screwdriver? Even an experienced user can tighten one side of the cartridge much more than the other - at least, I have. But not with a torque screwdriver.
You don’t have to use the stuff right away, or even ever. Just having it around will help. Imagine using it, get a friend or dealer to show you how, eventually install a $50 cartridge several times. Use it on a record that you don’t value much. And if you never do use the setup equipment, so what? One of my audio friends with a higher end system (but not quite where you are) won’t even think about it. His friends do it for him, and gladly.
Good luck and good listening.