With the exception of the kit lens which came with my camera, all my lenses are used - and from film slr cameras, using an adapter to mount them on my camera.
Photography is a hobby for me, and unfortunately there is no way I could justify hundreds (or thousands) of pounds for lenses which are way better than my ability. So far I have collected 80-200mm f2.8; 28mm f2.8 and 50mm f1.8 - all three for under £73, and one even came with a free camera.
If my skill level ever improves enough to justify better lenses then furry muff, but until then I will continue with these used lenses.