You asked
Is the fujifilm xf 150 600mm f 5 6 8 r lm ois wr worth buying used?
Here is what the site says about that.
From Fujifilm XF 150-600mm f/5.6-8 R LM OIS WR: Fujifilm XF 150-600mm f/5.6-8 R LM OIS WR: A zoom lens by Fujifilm for APS-C cameras, 150-600mm f/5.6-8. Specs - Maker: Fujifilm - Focal length: 150-600mm (zoom) - Maximum aperture: f/5.6-8 (it gets darker as you zoom in) - Made for: APS-C sensors - Mounts: Fujifilm X - Stabilised: yes - Autofocus: yes What it frames like - On APS-C (Fujifilm X): like 225-900mm on full frame; f/5.6-8 gives about the depth of field of f/8.4-12 there. Cameras ...
From Wildlife and sport: My picks: - Starting out: an APS-C mirrorless body with a 100-400mm-class zoom. The best value reach there is. - Hiking and travel wildlife: Micro Four Thirds with a 100-400mm. Light, long and stabilised. - Serious sport and birds: a full-frame body with fast readout and a 200-600mm or 150-600mm zoom. Buy used: long lenses hold their value and change hands a lot, and the savings are large. See buying used.
Quoted from this site's pages.