You've already established your max spending amount so that's a start. I would take every dollar of that and get the biggest bang for your buck. As a general rule AMD tends to be more for the budget gamers. I would think you could get at least a six core cpu, a 2-3gb graphics card and would highly suggest an SSD, they are very reasonably priced now and are a "game changer". If you want to save money I would do it with your case, don't get anything fancy and save from that, you should not have to pay more then $50 for a decent case.