I have had my white Xbox 360 since 2007. I have not played it for a long time and have found that you can pick them up for around £50 ($80 USD).
I plan on playing Gears of War 3, but I seem to recall my Xbox struggling with the previous generation of games (Gears of War 2, Modern Warfare 2 etc)..
Will the machine be fine, or is it about time I had an upgrade?