I found them on ebay and here, posting specs:
9mm Diameter FireBraid continuous filiment Fiberglass exterior sleeve for protection up to 1200°F.
Silicone Jacket Polyester reinforced insulation.
Extra thick boots for excellent life and to keep the elements from corroding the contacts.
Wound Core Mag-Wire 500 ohm/ft = maximum R.F.I. and E.M.I. protection @ 1/10 resistance of Carbon Core conductor.
Pure Copper wire available by request for racing applications.
Number marker and an included wire loom seperator to keep the wires tidy and looking good.
Dielectric grease is included to ease both installation and future removal.
Covered by Massive’s unbeatable limited LIFETIME WARRANTY.
Quality made in the USA!!!
So far sounds good to me, but not exactly unde $100 though, but still good price, comparing to Motorcraft.