A rousing “Yes!” to the 3 questions that burn inside each and every one of us:
Q: Are there castles in the US?
A: There are more than 300 castles in the US. [DupontCastle.com] 
Q: What does a castle cost and it it considered luxury housing?
A: You can get one for about $1.5M – I saw this listing for Wentworth Castle for sale in New Hampshire  which is also in the “300 castles” link above.
Q: Do people still build castles?
A: For only $300,000 – $350,000, you can build this castle yourself  in about 10 years.
Here are some questions answered by the owners of DuPont Castle in West Virgina.