Is the leica apo telyt m 135mm f 3 4 worth buying used?

Here is what the site says about that.

From Leica APO-Telyt-M 135mm f/3.4: Leica APO-Telyt-M 135mm f/3.4: A prime lens by Leica for Full frame cameras, 135mm f/3.4. The longest current M lens; precise focusing is easier with live view or an EVF. Specs - Maker: Leica - Focal length: 135mm (prime) - Maximum aperture: f/3.4 - 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, 135mm. ...

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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