I was actually surprised as well - I bought a powerful machine like 16 months ago, when i7 became available exactly to get a lot of RAM. At that time, 300$ got

I was actually surprised as well - I bought a powerful machine like 16 months ago, when i7 became available exactly to get a lot of RAM. At that time, 300$ got you 12 Gb. Also, SO-DIM became quite cheap: it is really affordable to get 8 Gb in a laptop (IMO, the difference between 4 and 8 is big because @ 4 Gb, running more than one vm on mac os x is not so practical, whereas at 8 it is a no brainer).