Anyone who drops a $500 lens is bound to be pretty pissed, which is why it'd be clever store it in the Beta Shell Lens Cases.
The Beta Shell Lens Cases are probably one of the best protectors for your lens on the market. The interior is lined with high-density, visco-elastic memory foam to protect your equipment from shock, scratches, bumps and any other unfortunate accidents that may spontaneously occur. It’s also waterproof, so don’t worry about dropping it into your pool, but try to make sure it doesn’t happen. The case also fits most sizes and models, so finding one suited for your camera shouldn’t be too much of a problem.
Since the lens is the most important part of the camera, it’d be good to have the Beta Shell Lens Case around. It’s sturdy and more reliable than standard camera bags.