Some people in this thread need to get off their high horses. The guy wants a cheap PC that can play BF4 and doesn't care about image quality. That's completely fair if that's what he wants. BF4 on low at 45FPS with a mouse and keyboard is still better than playing it on a PS4, not everyone has the same requirements as you do.
omminnoremac, you should have more than enough advice to make a decision. Enjoy BF4!
Not sure if you've read through all of this but he's had plenty of helpful advice and he's been nothing but rude. That's why things have got sour. Unfortunately I so what he wrote before it was deleted and it has no place here. No one is on their high horses, everyone who's tried and helped have just been told they are wrong by a 14 year old who's very rude, there's a limit to how much people can take!