Buying dvd's from ebay

Dvd’s are very expensive in Norway, so I was thinking it’s a good idea to start buying them from ebay. There are a few things I wanna know tho:

  1. What areacodes can I use? How do I know it’s compatible with my dvd-player?

  2. What can I expect to pay in tax & shipping? (for say a dvd-box of 0,7 kg, 25$)

  3. Any experiences with shopping from ebay?

Any help greatly appreciated!