Hello, I am thinking about upgrading my current MacBook to the newest MacBook Pro with 13-inch Retina display (base model: 4GB RAM, 128GB SSD). However, I want this computer to last for 3-3.5 years. Therefore, I am wondering how much difference does it make to have 8GB of RAM instead of 4GB? I am on tight budget so additional 200EUR for 8GB RAM and 256GB SSD is very debatable (there is no option to get only 8GB RAM configuration). My daily usage is very light, however: (1) I'd like to be able to play games like SimCity or Civ5, (2) sometimes I need to use "heavy" apps like IBM SPSS, (3) rarely I like to use photo editing apps. Any thoughts? Thanks guys!