the best you could upgrade your processor to is an older core 2 quad from ebay or dual core e7600 if you want to buy new. with your $300, approx $100 would be spent on the CPU and you will still not have something great, but much better than what you have. To max out the games you specified expect to need a new quad core processor from intel from the i5 or i7 range and new motherboard to support it. For a gfx card, it is unknown what these new games will require, but if you want to MAX them out you will probably need a gtx580 period which is WAY over your budget. Something that is in your budget would be an amd 6850 or nvidia gtx460, they should be able to play those games with med detail settings and will look significantly better than your crappy xbox. You are talking about unreleased games in which the previous versions maxed out the best gfx cards out at the time. Wait until they are released, look at some benchmarks, then decide what you want to do.