3 months’ salary on an engagement ring is not that much for a diamond ring. I’ve been diamond shopping with my auntie (she loves jewelry) and I know how much they cost. An upper middle-class woman living in say Carmel Valley would probably expect a diamond ring worth 50k up. Costco even sells diamond rings worth 100k +. I can guarantee you that no pretty woman worth her looks would take any less, ha.ha. (just joking)
In reality, diamonds are a dime a dozen and aren’t worth that much except that the DeBeers cartel limits the supply to hold prices up. Manufactured diamonds are just as good as real diamonds. The “worth” of a diamond is all psychology, marketing and artificially limited supply.