Is the ttartisan m 28mm f 5 6 worth buying used?

Here is what the site says about that.

From TTArtisan M 28mm f/5.6: TTArtisan M 28mm f/5.6: A prime lens by TTArtisan for Full frame cameras, 28mm f/5.6. A 19mm-thin pancake for zone-focused street photography. Specs - Maker: TTArtisan - Focal length: 28mm (prime) - Maximum aperture: f/5.6 - Made for: Full frame sensors - Mounts: Leica M - Stabilised: no - Autofocus: no, manual focus What it frames like - On full frame (Leica M): as marked, 28mm. Cameras it fits - Leica M9: Full frame ...

From Buying used: Buying used: Cameras and lenses are built to last, and many photographers upgrade often. That makes the used market one of the best ways to afford good gear. A body that's one or two generations old is often most of the camera for a fraction of the price.

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