I am going to get an Intel iMac 1.8Ghz now or August (Assuming that the iMac will not change in August). I can get the new 899 imac at a student discount. When I upgrade to 1GB, 160GB HD it is still about 300 less than the standard 1.8Ghz model. The only difference is the video cards. Is it worth 300$ to go from "Intel GMA 950 graphics with 64MB of shared memory" to "ATI Radeon X1600 graphics with 128MB GDDR3 memory". Or can I just upgrade it myself for cheaper?