One exception might be if you have a credit card that offers rewards, such as free points toward air travel

But are you ready to part with three months' salary as the diamond industry has traditionally suggested? If not, what's your magic number?

Figuring that out can be a stressful, high-stakes undertaking. Engagement rings come with unique financial and emotional expectations. And in a relationship intended to last a lifetime, it's the first big test.

"It does set a certain tone about whether a woman's expectations will be met by her husband or not," said ily therapist at the University of Southern California.

Even so, how much to spend rests in striking a balance between dazzling your beloved without tarnishing your future financial goals together.

Sit down with your partner and go over your short- and long-term financial goals. Beyond wedding expenses, goals could include saving for a down payment on a home, preparing to start a family, as well as retirement planning.

"This is the perfect entry point to see where each person's money values come from," said Michael Branham, a certified financial planner in Edina, Minnesota. "How are we going to put that life together and how does buying something like an engagement ring fit into that picture?"

First off, don't feel compelled to heed to the expectation that a ring cost three months' salary, the benchond cartel.

"That's actually kind of a myth that people somehow still believe," said Jamie Miles, editor of wedding planning website TheKnot.