Hi, I've decided I want to pick up a Nikkor 70-180mm lens, which of course isn't made anymore. I'm monitoring KEH's website, eBay, and my local Craigslist; but I'm wondering if there are other places people have found to be good sources for used lenses. I've seen two on sale this week. One is on Adorama right now, but seems significantly overpriced. The other one is currently on eBay, but is being sold by a pawnshop "no returns" with a description obviously written by a non-photographer. I'm not in any hurry, so I know I'll eventually be able to pick one up; but any guidance you can provide will be appreciated. Thanks!