both of these are wrong
for example, the xbox one gets 60fps at 720p on battlefield 4, and a $400 PC won't be able to do that
For the first part, I'm talking about at an acceptable resolution. 1280x720 is far from an acceptable resolution nowadays where we've reached 3840x2160.
As for the $400 computer, let's say that BF4 runs at the equivilent of PC's Medium settings at 60fps 720p. A $500 computer can best that. $400 most likely not, but you get that money back very quick through cheaper games and lack of needing to pay for online.
Edit: I apologize for doubleposting.