[Chronic Diarrhea]

In a few months I want to upgrade my processor. Right now I have a 1.1GHZ AMD Athlon. I am upgrading so I can play Call of Duty, and maybe a few others. I want something that will be affordable, but I have no clue how much processors cost. I don't even know if you can buy processors in your average computer store. I don't wanna spend over 200, but maybe in a few months I could spend as much as 500 total for an upgrade. Any suggestions? I feel like getting a 1.5 will be useless, as I will have to upgrade in another year. I'm looking somewhere around the 2.2 range. Other specs:

256 MB SDRAM
64MB GeForce Ti4200
20 GB HD

My mom has about $15,000 in her bank account, but I doubt she would be willing to give me $1500 to buy a new computer with all the latest tech. Also is now the time to upgrade, or should I wait until this fall to upgrade?