If you have no budget then don't just get parts over the next couple of months. Talk it over with the regulars here such as myself and we will help you put together a build that you will find awesome and not as much mula as you may think.
1500-2000 will get you a top of the line gaming PC and 800-1000 will actually give anyone pretty much a very good gaming experience.
Just remember though that if you want the best and to get the best value out of your parts plan to overclock....it's very simple and safe now.