It was all pretty reasonable assuming you have most of the basic tools already
Here's the components list:
--Canare L-4E6S at less than $1 per foot shipped (Performance Audio, or Redco)
--Two MrSpeakers plugs from the MrSpeakers web site (~$18 shipped).
--Neutrix NP3X connector (~$5, lots of places)
For the sleeving, which I think is identical to the stock cable sleeving:
--NMN0.19BK Flexo Nylon Multifilament - 3/16" - Black Splice Free ($13 for 25 ft at WireCare.com)
--NMN0.13BK Flexo Nylon Multifilament - 1/8" - Black Splice Free ($6 for 10 ft)
(Use the 3/16 for the main cable and the 1/8 for the smaller diameter sections after the Y split.)
-- 3:1 adhesive shrink wrap ($12
https://www.amazon.com/gp/product/B01C8I15EQ/ref=oh_aui_detailpage_o01_s03?ie=UTF8&psc=1).
(This is enough to last many years... Needs to be
adhesive shrink wrap. I used this to seal the cut ends of the sleeves so they wouldn't fray and to make the Y splitter)
So, for this cable, total materials were ~ $40-45.