If the bag is absolutely what you want, in brand new perfect condition, AND they're offering it to you at 2003's price, then definitely consider taking it. Otherwise, I'd say pass.
Date code IS important to me but that's because I'm anal about things ... If it's something that's 3 years old, I will have trouble believing that the bag has been untouched (yah I'm all about virginal bags). Also, I would wonder if there's something wrong with the bag for it to be sitting there for 3 years. For me, there'll just be lots of unanswered questions that would drive me nuts.