freedomlinux
macrumors 6502
They key difference is density. As the number of transistors doubles, they don't want the surface area of the chip to double, as the silicon wafer is their main materials cost.What difference does it make to the cost of the chip if it has 100,000,000 tiny transistors or 200,000,000. It's just a drawing etched into a wafer substance.
That means that more complex chips need to have smaller transistors. Even if their current machinery is capable of etching those smaller features, it requires higher precision and increases the chances that a defect might ruin the chip. (As a bonus, the smaller transistors also keeps the power requirements down)
With this increased risk, the production cost is certainly higher but yeah I doubt 2x. At some point, it's just profit optimization on the manufacturer's side - if they have enough wafers for X amount of chips, they'd rather turn them into products with a higher margin instead of older/smaller designs.
[As for calling it a cartel - no objection from me. The DRAM makers have been caught in price-fixing scandals etc in the past]