ok, noobie here needs the expertise and advice of everyone on the forum. i have the chance to buy the 24-70 lens at what i think is great price, $875. one thing about the lens that scares me is how old the lens is. the date code on the lens is UL 0809 which dates it back to 1997. should i take a risk on such an old lens? i'm meeting up with the guy this afternoon to take test shots with lens mounted on my camera. oh yeah, this is my first time buying a used lens too. what signs of wear and tear should i look for?