How can I say this and be gentle (like that was ever my modality to begin with). If you can upgrade your system for $100 and get better performance then I says go for it. But if you start talking $200 or more for legacy devices, then I say forget it. Once you start getting into the $100 then perhaps it's time to start saving for a new system. For $400 one could with the stuff you have now, upgrade to Sandiego core that will out bench both of your systems. For $500 you could get into dual core. So squeeze as much as you can out of what you've got and then leave it alone, it will soon enough become your backup system.