According to Numista, this coin is rare because they were forced to stop production. This is their quote: The silver version of this coin is the rarer of the ones produced by National Collector's Mint. It was released as a coin but Northern Mariana Islands being tied to the USA did not have authority to release a coin. It was ordered to stop being sold. The coin was designed by Daniel Carr. https://en.numista.com/catalogue/exonumia183799.html Is the coin legal to resell? Seems like a strange thing to have happen.
You can read more about it here, if you don't mind external links. http://moonlightmint.com/other.htm If you don't like external links, here is his telling of the tale. There is also a Wikipedia page on this as well. I haven't read everything on this controversy, so I really don't have an opinion, other than I'm not a fan of the design. https://en.wikipedia.org/wiki/Freedom_Tower_Silver_Dollar I believe that Dan did the design and engraved the initial set of dies, but didn't actually strike these coins. He says his design was modified and that Sunshine Mint / SoftSky Mint carried this series forward. There is a LOT more on Dan's site, and worth the read. Not ALL of the iterations of this design bear the DC logo, and keep in mind, this all occurred before Moonlight Mint got their Graebner press from the Denver Mint and really got into production. Dan's involvement seems to have started and ended in 2004, but production of these went on until 2010 it seems. Z