If I were to marry a horribly rich person (or a jewel thief), I would ask for this as my wedding band. According to the Hairpin, this is a posy (a.k.a. posie or poesy) ring– a simple band that has been engraved with a brief phrase or poem. Popular in England and France during the 15th-17th centuries, they were used as wedding rings and tokens of love or friendship.
Addendum: Oh, wait. Maybe 8,500.00 USD is not an over-the-top amount to spend on a wedding ring? I am completely clueless about this type of adult knowledge.