Thanks for the suggestion, Martin. With free shipping, the cheapest option with 1m cable and heat-shrink split is only eight times the cost of my current cable, over fourteen dollars more than the ES100 ($93.64) and only 60% less than my HE400i cost.
While I’m sure that the
high purity oxygen-free silver plated copper with a Teflon coating […] made with 4 strands of 26-AWG wire, braided in the round to reduce interference
is top quality, I’ll be satisfied with whatever conducts electricity in soft plastic with good strain relief and connectors - maybe even gold plated like the $12 cable (but with 2.5mm TRRS instead of 3.5mm with a 6.35mm screw-on adapter).