How comfortable would you feel with building your own? With the right guidance it's no way near as difficult as it may seem and you can often do it a whole lot cheaper than buying a prebuilt machine.
Head over to
www.reddit.com/r/buildapc the guys there are fantastic. All you have to do is list your budget and someone will be sure to help or definitely point you in the right direction. There's also a few websites where you can do a theoretical build and it'll let you know where to get the parts cheapest but the links to any slip my mind. The guys over in that subreddit will also help with any issues you have during your build too.
Just food for thought.