O>K >>Time to lighten up and play the photo trivia game.
What is the most expensive lens ever sold to a 'retail' customer (as opposed to one manufactured for NASA etc.)? If you believe the internet and petapixel.com in particular it was a $2 million for a 1600mm Leica lens. One of only two in existence it was allegedly sold to a Quatari individual with a large bank balance.
You might find the article in which I found this factoid interesting
http://petapixel.com/2015/07/20/10-of-the-most-interesting-lenses-in-the-history-of-photography/
