Prom season is about to get underway and while total spending for the event this year is down 6 percent from last year, the growing phenomenon of "promposals," or elaborate invites to the high school prom, are costing the average household $324 in 2015, according to Visa's annual prom spending survey.

'Promposals' are becoming more popular. (Susan Prentice, ThinkStock)

Promposals have become much more extravagant in recent years and now represent one-third of the $919 total that the average teen will spend on the dance this year.

"We have heard of everything from hiring an airplane to do skywriting to renting a billboard to hiring a clown to come to a school. Some are more outrageous than others, but certainly the cost that teens are spending just to ask their date to the dance is rising and it's concerning," said Nat Sillon, head of financial education for Visa.

According to the survey, families with a total household income less than $50,000 a year plan to spend $1,109 on the prom, while families making less than $25,000 will actually spend more, with an average of $1,393. Those who make more than $50,000 will spend an average of $799. That means that those who fall around the poverty line are spending about $600 more than those who are more well off and about $475 above the overall average.

"Prom is the perfect time for parents and teens to sit down at the kitchen table and have a conversation about how to set a budget and how to stick to it. Teens at that point in life are about to go to college or enter the workforce, and it's a great way to make sure they can plan for an event that's important without breaking the bank," Sillon said.

Other key findings of the survey:

  • Northeastern families will spend an average of $738 on prom night and an average of $431 on "promposal" for a total spend of $1169;
  • Western families will spend an average of $596 on prom night and $342 on "promposal" for a total spend of $937;
  • Southern families will spend an average of $544 on prom night and $305 on "promposal" for a total spend of $849;
  • Midwestern families will spend an average of $515 on prom night and $218 on "promposal" for a total spend of $733.

Visa has created a free app called Plan'it Prom which lets users make a realistic, detailed prom budget and then helps them stick to that budget by allowing them to track their spending as they shop. Some of the tips the app offers include the following:

  • Shop for formal wear at consignment stores or online. As with tuxedos, many outlets rent formal dresses and accessories for one-time use;
  • Have make-up done at a department store's cosmetics department or find a talented friend to help out;
  • Split the cost of a limo with other couples;
  • Take pre-prom photos yourself and have the kids use cell phones or digital cameras for candid shots at various events;
  • Work out a separate prom budget with your child well in advance to determine what you can afford;
  • Set a limit of what you will contribute and stick to it. If teens want to spend more than that, encourage them to earn the money to pay for it or decide which items they can live without.