Most MMCs replace base metals that cost a few dollars per kilogram. Gold currently trades at ~$37,000/kg. Even comparing against a relatively costly base metal like tungsten, gold is three orders of magnitude more expensive. Spending $100 or even $1000 per kg to halve the density of a given volume of material vastly increases the cost of aluminium, but greatly reduces the cost of gold.
I have absolutely no doubt that Apple could significantly reduce their materials cost by using this process.
Going back to the first iMac, their industrial design work has included developing or scaling new manufacturing techniques. Examples include co-molding white and clear plastic to get the liquid look of the iPod, and of course machining laptop bodies out of aluminum blocks.
If there is a company who could make this work at consumer scale, it's Apple.
Maybe not if you're Apple. It could cost them less to go through a complex yet highly optimized manufacturing process than to buy more gold.
http://www.ebay.com/gds/How-Much-Gold-Is-Really-In-A-Rolex-W...
We see that the golden Rolex has most of the weight in the bracelet and I haven't seen the "full gold" bracelet on the Apple site. The body of the golden Rolex apparently has cca 2 thirds of the golden ounce of pure gold, which is at the moment not more than 700 USD. If Apple can save a half of it, it's around 350 USD saved, not counting the higher expense to make a composite which would reduce the saving.
Now if we accept Gruber's guess that the most expensive watch will be priced in the order of 10 K USD, compared to all the profits per unit, it doesn't seem to be a big percent. But if we factor the expected number of the items sold it's not something that should be ignored. Still I can imagine that they could have simply made a body with the steel "reinforcement" inside and nobody would blink.
I sure expect somebody will properly tear down the Apple Watch Edition to measure the exact amount of gold. If Archimedes managed to do this 2 millenniums ago, why wouldn't we?
Like how foods made with "100% fruit" still have other ingredients.
I have a fairly cheap mechanical watch combined with a Milanese mesh strap. I ordered a bunch of different mesh straps, looking for the right material and closeness of weave - it's hard to tell from online photos. The biggest difference between the one I chose and the ones I discarded was weight. The discarded ones felt like they were made of plastic.
http://en.wikipedia.org/wiki/Metal_matrix_composite
"MMCs are nearly always more expensive than the more conventional materials they are replacing. As a result, they are found where improved properties and performance can justify the added cost. Today these applications are found most often in aircraft components, space systems and high-end or "boutique" sports equipment."
So it seems the goal was really first to have the more durable material.