tnabeDon't pay Apple for the RAM upgrade. Buy third party, install it yourself and pay half the price. (http://www.macsales.com is a good place to start).
This was great advice a year or two ago, now with all MBP retinas and airs, the ram is soldered onto the mother board, so yes upgrade to 16gb of ram.
processor speed is meh, i wouldnt pay $200 for another .3ghz
Do spend money on at least a 256gb drive, 512 would be awesome but very expensive.
Looking at the apple site though, if you're getting the mbpr with a graphics card, you have to get 16gb of ram and have to get the 2.3ghz and you have to get a 512gb ssd* (you might be able to downgrade ssd, but you definitely cant do cpu or ram, its weird).
So get the mbp that is 2599, get student discount and itll be 2399.