When you say "CPU," are you referring to the processor itself, or to the entire box that some people think of as the "CPU?"
If the former, may we reasonably assume that you are interested in building this system yourself, from parts? Are you familiar with or interested in overclocking?
If the latter, again are you interested in building a system, or are you looking for a pre-built unit in this price range?
Pre-built units in this price range will NOT be good for games, at least not the kinds of complex, modern titles that many of the forum members on this site like to play; nor will they be readily upgradable for games, without going to sufficient trouble and expense to have made it a far better choice to have built it yourself from the beginning.
Please clarify your intentions. Particularly if you are interested (or even willing; it's not that hard) to build it yourself, there is a sticky thread at the top of the New Builds forum containing a template containing a lot of useful information. Please fill that out.