If you don't need it, then why go through all the trouble? I bought the same MBP you have, at around the same time, and under the same circumstances (student discount). Funnily enough, I also have the same accessories as you do except the VGA adapter and extra Magsafe. I have the DVI adapter.
If you don't need the Core i5, then I don't think it's worth it selling it and buying a new MBP. You also have to remember the time/effort involved in transferring your data and reinstalling applications. For you, I doubt you can keep the MBP longer seeing as you are planning to sell it after one year. Resale value is negated since you had to add in accessories and those cost money too.
New stuff is better but do you keep buying new houses, cars, etc. after 1 year?