Core 2 Duo or Core 2 Quad?

Hi, I'm in Sri Lanka and will be buying a new computer. I am not sure whether to buy Core 2 quad or Core 2 Duo. Buying the core 2 Duo will save me around 10 000 rupees (is $100). I do play games and I plan to get a dedicated 512 MB video card along with a 3GB 800MHz DDR2 RAM. I'm just not sure on the processor. I think that for an average user (19 yr old student) a quad core does not presently offer any specific advantage over a core 2 quad? Thanks for reading and thanks for replying.