I just wanted to know if there were any parts that are better for a lower cost in this rig?
The Parts: http://teksyndicate.com/videos/build-best-350-gaming-pc-nov-dec-2012
Also before I would buy this, I would like to know, can it run games like Minecraft, Diablo and DayZ and also WoW and if so at what framerate/settings?
Framrates will vary according to detail and whats going on, minecraft will be easy, diablo 1 and 2 will be easy 3 may need to reduce details a little, Dayz/WoW would be the same depending on what your doing if solo probably medium settings if in a massive fight or lots of onscreen action you may have to drop a few details but it will still play.
Prices have changed a bit tho, so used diff RAM http://pcpartpicker.com/p/yXmH
I have seen the A10 - 5800k easily reach 30-45Fps in Battlefield 3 on ultra (While recording in 720p with 720p monitor), so I imagine none of the games stated would be a problem..Minecraft you may get framedrops simply due to the fact Mojang are too damn lazy to optimise their code and make it more RAM friendly.