People are not idiots. $140 for a 4GB 1200MHz kit is a ripoff. I can go out and get 4x1GB D9GMH/JKX sticks for less and know they will clock better than the G-Skill kit.

18 is # 1, don't do it. You will regret dropping $140 on that G-Skill kit, A lot of DDR3 kits aren't even that expensive.