The North Pole is the northernmost point in the world.
Crosscountry skis and dogsleds are about the only viable transportation option near the North Pole; staying with your tour group is advisable.
It is impossible to buy 'anything' at the North Pole; you should bring 'everything' you might need for your expedition. A small variety of beer, vodka, and whiskey is available in the Camp Barneo dining tent, at reasonable cost given the location (e.g. $5 for a beer, in 2013), as are souvenir t-shirts, until they sell out.
The North Pole's ocean-formed ice contains salt, making it unsuitable for drinking, even when thawed. BYOB. Celebratory champagne is traditional; vodka at -40°C while standing on an iceberg is also quite appropriate.
Although there are no permanent accommodations at or near the Pole, temporary camps can be set up, providing heated shelter for one or more nights. Barneo has semi-permanent heated shelters, which are commonly used by expeditions spending more than a day on the ice.