The Rolls Royce Of Cadillacs - The Leica Lens
Leica is the camera brand that when you finally have all the money you desire, they have something you'll want to buy. In this case it is the biggest brightest lens for the M series cameras - the Noctilux M 1:0.95/50mm ASPH. Even the name is superlative.
It is the lens for prowling dark nights. The 0.95 aperture has a depth of field of next to nothing at all but that next to nothing can be seen in a coal-hole at midnight. It is Otto focus if your name is Otto...otherwise you need to use the Leica M series rangefinder to zero in on the subject.
Your friends in the camera club will be envious of you. You will be able to ace the Street Photography Competition Night. You will be out so often at night that your family will assume you have become a cat burglar. Or a vampire.
And the best part is that somewhere there is a dedicated Leica team of designers and stylists who are probably working on an even bigger and heavier lens with an even fancier name. And their accountants are adding another zero to the price tag...