You get the 500GB HDD upgrade, and if you need a lot of memory, it might be worth it for the 50 dollars off.
But, if you are a student you can get a student discount at the Apple store. You can also take advantage of their back to school deal (free ipod) later in the summer. and, frankly, most of us probably wouldn't notice the difference in performance between the base model 13" and the i7.
If it were me I would take that same money you would have spent and either a) upgrade the base model to an SSD drive and/or b) upgrade the base model to 8GB RAM (i did this).
Waiting? I am not a big fan of it.