Something I never understood is that CPUs have a tiny die area (the size of your fingernail), but cost on average 4 times as much as a Memory DIMM, and a DIMM has maybe 20 or more memory chips that are each bigger than a CPUs die area, yet DIMMs are much cheaper than CPUs.
I know RAM chips are usually one generation behind CPUs for the size of the transistors, 32nm vs. 22nm, and there are much greater research costs for CPU development, but it still does not take into account the huge price difference per mm2 of silicon.