All cables are almost snake oil. Unless you live in a place with old wiring, the power cable is fine. I replaced the one for my DAC/amp only because it was too short for my needs. I went with the power cable for medical equipment. It was cheap and fire safety rated. And they need to not cause inference because of the medical equipment and alarms.
Internet connects depend on if it's analog or digital. Both, want a good build quality. HDMI, Toslink, and so forth, don't need to spend alot. Analog, has the added part of insultation for interference, but you still don't need to spend that much.
Speaker cables can be biggest sham of all. Other than build qaulity, only need something that is not microphronic. Is there difference between all copper, all silver, or some mix. Yes, but it's really not that big of difference.
Amps should be decent. It's what amplifying and driving the speaker. It needs to match well with the speaker. There's a whole rabbit hole between tube and solid state. There is a huge dimishing return in this area.
To me, spend the money on the one that that produces the sound....the headphone; technically the speaker. If it's crap, it'll be crap. Change the speaker, change the sound completely. Even here, the law of diminishing returns applies. You can get a top of the headphone, but it's not going to be night and day difference from a midtier headphone by the same company.
Since you're new(er), you should try to go to Headfi meetup, or set one up at a local library or something. Then you'll the chance to hear a variety gear from cheap, mid, and outright expensive. It's all sound good. The difference in all reality, will not be as large as you might think.
To me, spending $10K should get you multiple setups or gear. As you move forward, you'll figure if you need or want tubes, multiple headphones, flagship gear, and so on.