Recently I posted a thread about asking for a $800 budget and I'm just looking at every available option and something I was considering was when my friend built her computer she had parts that arrived DOA and she had to go through all the hassle of trying to find which didn't work and who to contact.
So, I was looking at trying to avoid this issue.. And something I was possibly interested in and not sure if this is a good buy or not is this prebuilt:
The prebuilt is using a FX-8120, a processor based on AMD's bulldozer architecture, which was pure shit.
It has a shit gpu, so you're going to need to upgrade that to play games.
The psu is shit, so before you can upgrade the gpu you need to upgrade the psu.
The motherboard is a shitty generic one.
So all in all, you're better off building your own.