These were bought from a "1 Man Band" eBay seller a couple of years ago.
Claimed they were cryo-treated high purity silver. I have no reason to doubt that.
He doesn't seem to be on eBay anymore.

Anyway - £25 a pair (RCA). £30 a pair (XLR).
All 3 pairs for £70.
Inclusive of UK delivery.

2 RCA pairs. 0.5m
1 XLR pair. 0.68m.

These do sound nice and open and well resolved.