Costs about $95 now, iirc. I recently bought one for one of my lenses. B+W filters are the ones to go for if you want to protect your lens yet get the max image quality from it, and if you have the moolah of coz. Why pay so much for a lens to put an inferior filter in front of it?
Is it worth it? IMHO, yes, a little pricy but this filter does a great job. Quite easy to clean also.