SSD is good for the average consumer and Memory is for VMs and power heavy apps. I would get an ssd and memory because as other people said, you can get 8 GB or 16 GB for cheap.
8 GB
http://www.amazon.com/Komputerbay-S...UTF8&qid=1350180651&sr=8-16&keywords=8+GB+ram
16 GB
http://www.amazon.com/Komputerbay-P...TF8&qid=1350180618&sr=8-15&keywords=16+GB+ram
8 GB
http://www.amazon.com/Komputerbay-S...UTF8&qid=1350180651&sr=8-16&keywords=8+GB+ram
16 GB
http://www.amazon.com/Komputerbay-P...TF8&qid=1350180618&sr=8-15&keywords=16+GB+ram
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