Sotha Sil's designation of this mountaintop laboratory as the "Orbservatory Prior" clearly indicates that the site was an experimental or test version of what he had in mind—though whether he ever built an "Orbservatory Final" is unknown.
Crown Store items are purchased in the in-game Crown Store. To buy any of the Crown Store's special items, you'll need crowns, a virtual in-game currency. Crowns can be purchased in packs of various sizes, and you'll receive a discount on larger packs!
You can get a monthly allotment of Crowns by signing up for an ESO Plus membership! Learn more about member benefits.