Is the leica elmar m 50mm f 2 8 worth buying used?

Here is what the site says about that.

From Leica Elmar-M 50mm f/2.8: Leica Elmar-M 50mm f/2.8: A prime lens by Leica for Full frame cameras, 50mm f/2.8. A collapsible 50mm, made until 2007. Specs - Maker: Leica - Focal length: 50mm (prime) - Maximum aperture: f/2.8 - 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, 50mm. Cameras it fits - Leica M9: Full frame - ...

From Leica Elmar-M 24mm f/3.8 ASPH: Leica Elmar-M 24mm f/3.8 ASPH: A prime lens by Leica for Full frame cameras, 24mm f/3.8. A small, slow 24mm and one of the cheaper Leica wides used.

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