Not really. The RAM is biggest factor at only 4GB. But, you could always upgrade RAM later and toss another 4GB for another $20, but 4GB runs most modern PC games perfectly fine. My current set up with a 7960 only has 4GB and I have no problem running everything at near max settings including Far Cry 3. At the very least this set up would probably out perform what these current console specs are rumored but you have a system that is more upgradable in the future.
I'm assuming most people have a keyboard and mouse lying around somewheres. But you can also use 360 or PS3 gamepads on PC relatively easily. I consider those kinds of accessories to be the same thing you'd face with a new console with buying battery packs, and extra controllers, online fees, HDMI cables, etc.
You would have to add costs for a copy of Windows 7 or 8 but if you already own a copy on an old PC or laptop/netbook you could just use jellybean to get the serial key and do a fresh install. Win 8 is also pretty cheap right now, especially if you are a student.