Apple is simply going away from 3.5 mm connected headphones to drum up more business. Headphone sales are stagnant because once people get a pair they like they stick with them. Take away the 3.5 mm jack and you force people to buy new headphones.
Don't kid yourself into thinking Apples motives aren't purely profit driven. Apple pulled out of the iPod market for the most part, tablet sales are flat and iphone sales are dropping along with profit. Accessories like headphones have a higher profit margin than electronics do for the most part. Apple is struggling to find new revenue streams and headphones are one of them.
As for Sony's use of copper on the 1Z it is another marketing ploy to trick buyers into thinking it makes a sonic difference. Aluminum goes for about $0.71/pound US current price, copper about $1.75/pound US. The 1Z weighs just over one pound so basically the copper casing adds about $1.04 to the cost of the 1Z over using aluminum on the 1A. I have no idea how much gold plating Sony is using on the 1Z but again gold plating on the outside of the DAP will have no sonic benefits at all. You can buy 24 karat gold plating solutions for as little as $100.00 for 32 OZ (4800 sq inches) to the public so even less for Sony in large quantities. So gold plating not nearly as expensive as it looks. Nickel is about $4.00/pound and you won't need much on a device this small so lets say another $0.50.
The marketing guys can try to spin it any way they want but it all comes down to justification for gouging Sony customers. Per 1Z unit $1.04 more for copper (over aluminum), maybe $0.50 for the layer of nickel and lets be generous and say 8 oz of gold plating per 1Z ($25.00). I come up with $26.54 in added cost, lets round up to $30.00 to be safe over the casing for the 1A.
More expensive TF capacitors about $0.64 each vs about $0.30 for OSCON capacitors on the 1A Again maybe a few bucks difference. So lets call it $35.00 for everything so far. Adding another 128 GB memory chip into the 1Z maybe another $30.00. So even if my estimates are a little low at $65.00 lets call it $75.00 per unit higher production cost for the 1Z over the 1A. That is an obscene amount of profit on the 1Z over the 1A even if you double my estimates.
Still think the 1Z is worth the premium price? At least be smart and wait a few months until the price comes down if you are still serious about it.