Here's Kim Kardashian, navigating her way through LAX amid an enormous mob of paparazzi, carrying her extremely rare Hermes So Black Birkin, and we've seen her carrying this coveted Birkin before. Kim is quite the collector of exotic Birkins, in fact, it could easily be argued that she's one of the most prolific Birkin collectors, because she has both the wealth and the high profile necessary to gain access to the really good stuff.
Kim does occasionally liquidate some of her Birkin assets, presumably so she can acquire even more Birkins. Here's Kim with a 30 cm Himalayan Crocodile Birkin earlier this year, a bag which is rarely seen in the wild. You can view the majority of Kim's Hermes investments (some of which are now owned by other Birkin/Kardashian paraphernalia collectors) in "The Many (Many) Bags of Kim Kardashian."