Give me a good Gaming PC build?

I have been trying for a long time to design a good gaming PC rig, but I can't seem to get it right. If possible can anyone give me a good gaming PC rig between $500-$800. Also any tips for a first time builder would be great.

P.S (This would be used to play games like: BF4, LOL, WoW, SC2, DayZ standalone, Arma 2 and 3, Most steam games, Minecraft, etc…). Also if possible you can also post pre-built PC's with the same price range.

Issa

You gotta check "refurbished" PC shops. They do have decent gaming PCs in that range. I don't think you could ever find a new gaming PC at those prices. Anything with an Intel-i7 processor is over a thousand bucks. The latest video cards, etc. Are very expensive.

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