Yeah, that's the problem with the dual core g3258, for single thread games which need only 1-2 cores, for the price, its damned near unbeatable, with easy OC of 4.5 or better, with good cooling, you are looking at 1/2 the price or lower of a quad core system. But thats where some of the issues start. Many games, especially mmorpg's or other multi-player games rely heavily on quad core processor power. In those games, the g3258 isn't in the back seat a such as it's in the trunk. High OC can go a long way to make up for this discrepancy, but that only occurs under 1 situation. Good cooling.
Since the g3258 is only 54w, it'll not need a massive cooler to do the job. A hyper212 EVO is a 180w cooler, and the $35 cryorig H7 closer to 200w. That's much more than what you need, but at the same time Over-cooling is a good thing. It means that whatever punishment the cpu can dish out heat wise will never be enough to drive the cooler to its max. So slower fan speeds, less noise, plenty of cooling capacity, all from a budget cooler.
Raijintek Ereboss or Aidos or Themis, Enermax T40, CM Hyper212 EVO / plus, Cryorig H7 are all in that same performance /price range. You'll just need to figure out case clearance as some of those coolers are 160mm tall and don't fit in some cases. The Aidos and H7 will fit all but the slimline, being only 145mm tall.