The main problems I face is the motherboard only supports up to 4gb Ram and the Core. The compatible Graphics Cards are also very expensive. My goal is to Spend as little money as possible to upgrade this machine for Gaming(Skyrim/BF3).
I want to know if it's worth it and what kind of performance I can get out of it.
I would recommend you to just buy a whole new since you won't be able to get any decent frame rates from your build even after upgrading. You can build a pretty good computer for around $600. You could also probably reuse your HDD if it's SATA to save some money