You can get by with a 2008 MBP, but really I think it is a poor investment. It would be 3 almost 4 years old. You can still use it now but in a few years it might become unusable whereas buy a new MBP now would mean you could still use it for 6+ years. Assuming you still have access to your college email account you can get a 15" MBP for $1700 and you can get the $100 Mac App Store gift card as well as a free printer after $100 dollar rebate. If you are settling for a 2008 MBP you don't need the $2K model MBP. The only way I would buy the 2008 MBP was if it were less than $600 anything more and I think it is worth spending the extra money.
You definitely have a point. I'm still thinking about what I should do because I'm not sure how much life a 2008 MBP would have left.