Just when you were getting used to the idea of leaving the house in more than one layer, Dallas-based, mega-luxe department store Neiman Marcus thrusts the holidays upon us. It’s that time of year again: The 2006 Christmas Big Book has arrived. The emphasis is really more on the ooh-and-ah worthy spreads than on buying, so it seems. DVF dresses, Cole Haan satchels, David Yurman gems — they’re all there, even crystal-embellished barbell and jump rope sets. But the real appeal comes with the various over-the-top, one-of-a-kind offerings featured: A chance to charter a Virgin Galactic to space (at $1.75 million), an all-star sports celebrity package (starting at $250,000), and a His & Hers Twike commuter vehicle ($40,000).