I'm not sure I would spend $100 to upgrade from a dual to a dual. More so if they both have a similar arch. I know you have an SE model, but can you OC your 2.2 to 3GHz or so? Perhaps you should spend $30 on a Hyper 212+ and OC your current CPU to 3GHz+.
I've had some problems with overclocking this CPU in the past so I don't mind spending a bit for a new processor. But nothing above $200.