Gaming PC possible builds 1000$-1500$

I am a xbox 360 gaming veteran and I am wanting to get into PC gaming. I want to play minecraft, arma 2 and 3, DayZ, and possibly COD Black Ops 2. I have no clue on what I should get computer-wise. I do know that I would prefer to buy the parts and a friend and I will put it together. I have put a price range, but I would like two different estimates (one for the $1000 and one for the $1500. They don't have to be exactly those amounts just not over 150$ more or less. I would greatly appreciate any positive feedback and input from anyone.