I looked at it this way. I have bought a few Zuikos between 18-135mm slowest apeture 3.5 of the 18mm.
Now if you need AF unlucky its gonna cost you thousands.
Canon 50L over a grand - Zuiko 50mm f1.2 cost 250 quid
Canon 85L well well over a grand - Zuiko 85mm f2 cost 120 quid
Canon 135L not cheap - Zuiko 135mm f2.8 cost 150 quid
Or the 24, 28, 35, 100mm f2,s that i got for less than a grand
I suppose some people can not be bothered with manually focusing. Its saved me thousands of pounds and improved my keeper rate over night.