43rumros Steve sent me that picture from the Photo Festa 2014. You see the Olympus 300mm f/4.0 size compared to the Canon (here on eBay) and Nikon (here on eBay) lenses. That’s the price and size you pay for Full Frame lenses :)
And also DC.watch posted some pics of the event. So here they are:
UPDATE: I corrected the ebay links ot the Canon and Nikon 600mm (and not 300mm) lenses.