The average cost of attending a US-style high school prom (or school leavers' ball as they are often called in the UK) now stands at a whopping £186.
Last year, the cost was £154, on average, meaning school leavers are forking out 20% more on their big night out than their peers did last year.
The bill for girls comes in even higher, at £204 a year, according to research from comparison site Gocompare.com. That's up from £176 last year. And 10% of parents admitted to spending more than £400 on sending their little angel to the ball in style.
The cost of attending is a bit lower for boys, at £167 on average. But boys are paying more than they did last year too. In 2013 the costs amounted to just £131.
It falls to mum and dad to pick up the tab for three-quarters of the cost, but nearly half of parents admit to picking up the tab for everything.
Some 24% of parents said the prom was a drain on their household budget and 12% admitted to spending too much. And 10% of them would prefer prom nights to be banned altogether. However, just over a third were pleased their child had the opportunity of attending.
Agree a budget
Claire Peate, customer insight manager at Gocompare.com, said: "Parents should discuss the matter of money with their children and consider agreeing a budget with from the start so that spending doesn't get out of control.
"Other ways to save money could include picking up a prom dress from a clothes exchange or websites like eBay instead of buying new, and a pre-prom hair and make-up party for girls may be an entertaining and cost-effective way to avoid paying for professionals."
With 83% of 16 to 19 year olds in the UK having been or going to a high school prom this year, compared to 59% last year, the popularity and costs of attending look set to continue to rise.
So what does the cash get spent on?
84% of girls have a new dress, 75% of boys have a new suit
61% of girls and 50% of boys have a professional hair do
36% of girls and 28% of boys pay for a fancy car journey
32% of girls buy flowers or a corsage, 19% of boys buy them for their date
27% of girls have a their make-up professionally done
22% of girls and 8% of boys have a spray/fake tan
10% of girls and boys host a pre or after prom party
10% of girls and 11% of boys arrange unusual prom night transport.