For 300-400 dollars you get an entry level laptop with a Core i3 CPU or a low end AMD APU. I don't know if that's good enough for your game. My guess is that anything modern and graphical simply will not be usable. Make sure you get the 37watt TDP Intel CPU instead of 15watt TDP CPU. The former are faster. I'd consider a laptop with AMD A10-5750M APU without dedicated graphics as the minimum system for a quasi-modern game, but even those may cost in 500-600 range.