Building a PC

[Sanderz]

It would be nice of you to list all the brands. The prices are from newegg unless specified.

CAS: $55 Its a cheap case so expect a flimsy aluminum frame and poorly fitting bays.
CD: $30 Who needs a burner nowadays? Other than archiving (which an external hdd would be better), just use flash memory.
CPU: $300
Cooling Fan: $58 (amazon) lol shitty water cooling. Get a good heatsink instead.
HDD: $60 (seagate green) - $110 (WD black) You didn't specify brand but I'm hoping you don't cheap out on this only to have your hdd fail in under 2 years.
MEMORY: $70? I don't believe that corsair has a xms variety of that memory at that size/frequency. I can't find it anywhere, so it may be OC. Anyways, 2 x 8 GB would be better so you can upgrade later.
MOTHERBOARD: $140 ASUS is good
OS: $140 Stick with windows 7 for now.
PSU: $50-120 Hopefully its from a reputable brand. A Corsair psu is $65 while a Cooler Master one is $100.
VIDEO: $160-180 Brands don't matter too much here.

That adds up to about $1100. Your builder probably gets windows keys cheap and probably buys some of those parts in bulk. It doesn't sound like hes gouging you on labor costs.