Artifact level treasure (Now the weapons artifact thread)

Spit balling this but for ideas but a few examples from real world: <div><br /></div><div>The Messiah Stradivarius: 300 years old, in &quot;new&quot; condition, valued at 20 million dollars.</div><div><br /></div><div>Gutenberg Bible last sold in 1978 for 2.2 million dollars</div><div><br /></div><div>Similar things in setting should: </div><div>1. Be one off or unique in some way</div><div><br /></div><div>2 have a value that starts in the neighborhood of 1 million Cr</div><div><br /></div>