I agree with Dyers Eve that the $550 "gaming" PC shouldn't have non-gaming scores considered when looking at its overall value; if intended to be a general purpose PC, different component choices would probably have been made. For those willing to turn down some eye candy, and simply enjoy the gameplay, it looks from the benchmarks as though even a lesser GPU could have produced playable frame rates.
Still, this isn't a be-all, end-all analysis, just like any other build article. It adds more data to the "index;" I think we can all see how we might change any of these to make them better for a specific purpose.
In any case, I've entered, and wouldn't mind winning any of these:
$550 PC: Would go to my father, although possibly with a lesser GPU, as he doesn't play demanding games.
$1000 PC: Built in an Enermax Hoplite, this would become my new primary PC. I'd add a SSD to it and possibly use a Seasonic X-560 for efficiency.
$2000 PC: I'd pull one GPU and add a 500+GB HDD, build this in the Hoplite, and it would become my primary; likely also with the X-560.