When I bought my first Macbook in 2009 (the unibody) it had a 160GB harddisk. The 250GB upgrade would cost €150 more I believe. I bought the 160GB version, went to the nearest IT shop and bought a 320GB disk for €120 and got that 160GB as a spare.
I remember selling it and overall making a profit on it after 2 or 3 years of use.