You asked
Is the sony e 11mm f 1 8 worth buying used?
Here is what the site says about that.
From Sony E 11mm f/1.8: Sony E 11mm f/1.8: A prime lens by Sony for APS-C cameras, 11mm f/1.8. Specs - Maker: Sony - Focal length: 11mm (prime) - Maximum aperture: f/1.8 - Made for: APS-C sensors - Mounts: Sony E - Stabilised: no - Autofocus: yes What it frames like - On APS-C (Sony E): like 16mm on full frame; f/1.8 gives about the depth of field of f/2.7 there. - On the larger-sensor bodies of Sony E: ...
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.
Quoted from this site's pages.