I just received my MDR-EX600 this week (after learning the whole dynamic IEM line was being discontinued by Sony).
One of the first reactions I had on unboxing my IEM was -- whoa! Those are some scrawny looking cables!
So I figured I better get at least one replacement set now while there's still stock around.
Surprisingly (not!), I didn't find any Baldur MKII offerings. Unscrewing the OEM wire from the IEM showed a proprietary connector. And so...
Sony support: 239-768-7691. Yes, they had a replacement cable, RK-EX600LP, available and in stock. $55.52 + tax + shipping.
I also asked about the thicker Japanese-market-only version, the RK-EX1000LP. Currently on backorder (in Japan); US price $159. today. Hmm...
So, let this be a reference post going forward for people who need a cable replaced for either of the above headsets. In the US, both the EX1000 and EX600 ship with the cheaper EX600 cable.
It'll be interesting to see what price changes may occur in 6-12 months: bigger markup? Inventory closeout?