Right here in the marketplace section. You DID browse the forum before posting, right? Please tell me you did? Or did you just do the lazy thing and immediately post without even looking? Or for much older lenses, the shops at Peninsula mall.
As an example, just saw an ad for d60 & 18-55 kit lens for 500, seller says no lowballing, do ur research. I was browsing at the peninsula shops few weeks back, a much newer d3100 (2 generations newer than d60) was selling at $500 with the newer 18-55 VR kit lens, and with a few months Nikon warranty.
If u have no confidence in knowing how to see lens condition, best is buy from shops. The reputable ones clean properly and ensure 100% working. At least u r paying for assurance and some after sale service.
I'll remember your nick for sure dude. Obviously you have something lacking in here; your understanding on 2nd hand lenses. And where do you get the idea of old lenses lacked clarity due to scratches? How do you term 'old' by the way?