The problem here is a bit more insidious than you might assume at first glance. The reason you can buy a motherboard for $100 which has close to a thousand individual components soldered to a 16 layer board is because a manufacturer invested tens of millions of dollars in a highly automated manufacturing line that could turn out millions of them a month, and all the connectors on them had injection molds made because billions of connectors would be needed, and testing companies built amazing bed-of-nails testers that can run 25,000 tests on that board.
When I was at NetApp our partners built systems for us (so called ODMs) to our specifications but in the thousands, not the millions, and our motherboards that had a similar complexity to the ones that Gigabyte or ASUSTek could sell cost us $800 each. Smaller runs, those in the hundreds, are like $2,500 to $3,000 each.
The lack of buying is taking the oxygen out of the system. These guys are cutting costs where they can, but there will come a time in your lifetime where buying a cost effecting "PC" class machine out of parts will be very very hard to do, they just won't have the volume. A new TV with similar smarts? Still cheap. But a desktop machine?
They call them economies of scale, when there is a scale, when there isn't they don't work so well. Factories in China are starting to switch over to making systems for server farms, not individuals. Amazon, Google, Microsoft might by 50,000 at a time. You and I, not so much.
We are on the leading edge of that change. I have a sense that it is going to be a fairly dramatic change.