That's because you get 64GB more flash storage.
For me, 64GB storage won't work on a laptop. That's the whole memory. After you install Mac OS SL, then it will be like 50GB or less.
50GB? Yea.
Well i know you get 64 GB more flash storage. But, for new models, the 4GB/1.4GHz/64GB is $1099 while the the 4GB/1.6GHz/128GB is $1299, a $200 difference. My point is just that the difference is even greater than for new ones, and since I was only planning to use the Air as a secondary machine (and not a media machine), I decided I didn't want to spend the extra money for space. 64 GB is plenty for some homework (documents) and websurfing .