I agree with oldschool and plug wires have gotten decidely high tech. Back when I was in high school we use to just buy the stuff from the parts house and make our own. They sold wire by the foot in various colors, wire ends, and wire nipples on the cheap.
Back in the 70s we had a 28 cylinder aircraft engine in the airplane shop and consider the plug cost replacement on that in today’s dollars.
14 bucks apiece at the time X 28 cylinders X 2 plugs per cylinder = Ouch.
And that’s not including any labor or magneto tune-up parts.