Made up a pair of these based on some half-baked Eichmann theory (Keith - not Adolf).
Used 50c Jaycar RCAs - not for cost cutting but on the minimal metal theory (real Eichmann plugs would probably be better)
For the rest, 1 metre of solid core Cat 6 cable, separated the strands and somewhat de-kinked them.
Then braided using 2 strands for earth and one for signal, kept it simple, solid colour wire for signal and 2 x striped ones for earth. Soldered connections both ends.
Doesn't sound too awful either, very clean, perhaps a little lightweight in the mids.
Total cost < $3
Pic is a bit fuzzy - sound isn't