Thanks guys, for your opinions and advice, it helped me to make my buy decision. I bought the 70-300 IS USM f/4-5.6 from the guy on craigslist. Like the seller said, It was brand new, the box, documents, and lens all had matching serial numbers and the seller even had the reciept. This lens came bundled with his new camera, and since he already had a telephoto lens he didn't need this one. I paid $300 for it, so I saved money on it. While $300 isn't inconsequential, in the realm of Canon lenses $300 is not much. I have decided however, that If/when I buy an L lens or any lens in the price range or higher I will buy new, and from a reputable dealer, which will eliminate doubt and my own second guessing.
Regards,
Rick
New EF 70-300 IS USM f/4-5.6 f/10 1/500, ISO 250, 135mm




