1) I used 2 sticks of 4 at first, but found a deal for the same kit for cheap on black Friday, thought what the heck, why not.
2) I have no intention of overclocking a CPU. Never needed to
3) The cost is irrelevant, I just wanted to list the parts. Its all in an NZXT Phantom 410. Didn't list everything as there are things like extra drives, DVD reader, fan controller, etc.
4) I bought the drive refurbished on Newegg