Some of Hermès' rarest Birkins are up for auction — with many expected to go for more than $100,000

• Christie's luxury handbag auction is underway, with some Hermès bags expected to fetch six figures.
• The auction highlights the high demand and limited supply of Birkins that drives up their value.
• Luxury handbags have become an investment piece akin to art or watches.

If you're in the market for a Hermès bag that doubles as a doll house, you're in luck — as long as you have $100,000 or so to spare.