Caved in and bought an expensive diamond. What really counts here is social ideas of what is necessary. You can push against but most people will do what's socially the done thing. I shudder to think what horrible things we might be able to get people to do as a gateway to getting married. Eg the Spartans had to murder a Helot to graduate IIRC. What if you had to beat up a random person to get married? People would still do it I think.

Not long after I got married, I read about Moissanite.