If you watch the gold video (or read the article), you'll see they're not using anything remotely similar to the process in that MMC patent. It's essentially a conventional alloy, mechanically hardened.
A Rolex submariner weighs about 135g. Let's pretend that all but 35g of it is gold (it's less, but w/e). So we're at 100g of 18k gold. Now, 18k gold is 75% by mass, equal to 75g of 24k gold or $2900.
The cheapest, non-gold submariner costs $7500.
Buying gold watches to get the gold - or even considering the value of their alloys when buying them - is as dumb as doing the same with computers.