• Nearly everyone agrees that Britney Spears and Sam Asghari should sign a prenuptial agreement.
• In fact, many couples can benefit from hashing out certain financial matters before tying the knot.
• A solid prenup can even help you stay married, one expert says.

Millions of people congratulated Britney Spears on her recent engagement. Almost as many urged her to get a prenuptial agreement.

Her fiancé, Sam Asghari, was already on board.

"Thank you everyone who is concerned about the prenup! Of course we're getting an iron-clad prenup to protect my jeep and shoe collection in case she dumps me one day," he wrote on Instagram.

In fact, the singer's assets are valued at more than $50 million, which makes the pop star and her long-time love obvious candidates, but fame, fortune and a financial conservatorship aside, most couples can benefit by sorting out some money issues before tying the knot.

"More people could benefit from a prenup than we typically think," said certified financial planner Stacy Francis, president and CEO of Francis Financial in New York. 

For example, prenups, which generally safeguard real estate and investments holdings, savings accounts or a business, can also offer the chance to hash out how a partner could be compensated for leaving the workforce to care for their children.

The average cost of a prenup can range from about $1,200 for low-cost, simple agreements to $10,000 for more complicated matters.

"Part of a definition of a marriage is an economic union," Francis said. "It helps lay out the terms of the economics of the marriage."

In addition, it's increasingly common that there are complicating factors, including children from a previous relationship, a family business, real estate and investments holdings, or one partner's student loan or credit card debt.

For millennials, in particular — now saddled with $1.7 trillion in outstanding student loans — that may be reason enough to consider such a protection.

A solid prenup can even help couples stay married, according to Penelope Hefner, a family law attorney and principal of Sodoma Law Union in Monroe, North Carolina.

It's an opportunity to have those conversations about money, she said. Doing this before getting married gives each person a better understanding of what's most important to their partner as well as the chance to discuss and set shared goals.

"Everyone brings something to a marriage," Hefner said. "A prenup agreement affords security in knowing your partner values you and what's important to you."