Display Sets - what to get?

I'm looking for something big and that is fairly easy to access and doesent cost twice the retail or worse.

I was thinking about

• Hogwarts Castle (top1 at the moment)
• Technic Range Rover
• Republic Gunship UCS
• Porsche 911 Creator Expert
• Gingerbread House
• NASA Space Shuttle (top2 at the moment)
• Medieval Blacksmith

I would like not to spend more than Hogwart's or Gunship.

Let me know your thoughts.