I always keep a watchful eye on the For Sale Section of the forum, for deals on used Canon Lenses. Additionally, I keep in tune with the prices of which they go for new (Adorama, B&H, Amazon).
Why do some people sell used Canon Lenses for only $5-$15 less than the new price, and buyers still buy them? These are lenses which are in-stock at the retailers.
Is a savings of $10 worth buying used?
Help me understand this...

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