How the high school prom, imported from the US, has overtaken the end-of-term disco

ON A sunny Thursday afternoon the rustle of taffeta can be heard over sporadic "oohs" and "ahhs" coming from the changing rooms of Butterflies, an unassuming eveningwear shop in Edinburgh's Grassmarket. Owner Fiona Brown and her two staff are kept busy with a steady flow of young women trying on floor-sweeping gowns for balls, weddings and, most popular of all, school proms.

• Formal proms with suits and gowns are now the norm for school-leavers, but mothers and daughters, such as Lindsey and Doreen Strachan, above, have found that gorgeous frocks needn't cost a fortune. Picture: Jane Barlow

In the back, next to rails of dresses ready to be posted off to teenagers across the country, Fiona shows me the "prom book", a hefty folder listing the dates of almost every school prom in Scotland, and even parts of northern England. Whenever a girl buys a prom dress from Butterflies (which is often: Fiona shifts 700 every year) details of the dress go into this book, to ensure that she doesn't sell the same dress to two girls attending the same prom.

It may seem a little extreme, but in the past decade the school prom has been elevated from a simple dance in the school gymnasium to a slick event that takes up to a year to plan. Originating in the United States in the 1920s, it is now a firm tradition here in the UK. Most take place in a local hotel, with groups of teens hiring limousines to get there. They pay for the meal, and sometimes even book a room. That cost, however, pales in comparison to the money shelled out on dresses, shoes, accessories and beauty treatments.

Lauren Stalker, 17, from Corstorphine, who attends Craigmount High School, paid 160 for her dress, with the cost of accessories on top of that. "My gran paid for my dress, and I'm lucky because my Mum's a beauty therapist, so she can help me out with that side of things," she says.

"Most of my friends are getting a spray tan and some people are getting their nails done too. A friend who's a hairdresser is doing my hair and all that's left to sort out is the final fitting for my dress, which I bought in January. I've been thinking about the prom for a while; we all arranged our dates in fifth year and started thinking about dresses back in November. It's the last time that we'll all be together and we just want it to be an amazing night."

Lauren's mother Jennifer was more than happy to help out. "I've really enjoyed the whole process," she says. "I've got two older boys so this is the first time I've been able to do something like this. I probably think that parents have to shell out a bit too much but, overall, it will be great to see her all dressed up. I can't wait."

Though most girls will go shopping for their dresses with friends or female relatives, for some that's not enough. The Glass Slipper is a personal styling service operating in Edinburgh offering a service tailored specifically to teenagers. They charge 190 for a two-hour shopping session, where a stylist advises these young clients on cut, colour, size and overall style of an outfit.

"We are inevitably approached by mothers who want to smarten up their daughters a bit," says Nina Cooke, the owner of The Glass Slipper. "Their end-of-year dance is a very big deal to them and they'll spend anything from 200-600 on their outfits, on top of our fee. Some parents will also get them a make-up lesson, which costs 190 for two hours. We show them how to dress for their body shape, which colours to choose and how to put together the whole outfit."

For Fiona Brown, the increased willingness of parents to spend hundreds of pounds on their daughters' proms has been very good for business. Her dresses sell for around 150-400, and they're geared to fulfil even the frothiest of fairy princess fantasies. Some dresses come in up to 60 colour choices, and there are myriad styles to choose from – all bright, all sparkly. Popular styles this year include slinky floor-sweeping numbers, short, flirty dresses with full tutu skirts and full-skirted floor-length tulle dresses in candy colours.

"We've been open for 17 years, but we've noticed a real surge in sales of prom dresses in the past five years and it's now a huge part of my business," says Fiona. "The girls' mothers are almost always more than happy to pay for their dresses. They enjoy the whole experience of seeing their daughter all dressed up, possibly because people are less likely to have formal 21st birthday parties these days. This year, however, I've been really surprised to notice a big upsurge in Primary 7 girls buying expensive dresses for their leavers' dance before going into high school.

"I've had mothers spending up to 200 on a dress for their 12-year-old daughters. They're not so happy about it, but I think that there's a bit of competitive parenting going on there."

Where high school proms are organised by a committee of pupils under the watch of the school, "mini proms" are becoming increasingly popular among primary school pupils leaving for high school. These, however, are generally organised by parents, and are not sanctioned by the schools, who tend to view them as problematic, exclusive and an excuse for parents to show off, simultaneously raising the bar on spending.

Doreen Strachan, also from Corstorphine, was determined that her daughter Lindsey, 17, would have fun at her high school prom, but was reluctant to let the spending get out of control.

"I have three daughters and the youngest is in sixth year at the moment. They all went to the same school and all of them want roughly the same things for their prom: the dress, matching shoes, jewellery, handbag, fake tan, hair up and their make-up done," she says. "I've probably spent around 200 in total on each of my daughters for their proms, but on average I think that parents spend a lot more. Certainly they spend a lot on their dresses; one of my daughter's friends spent 300 on hers. I do quite enjoy it because it's such a big thing to them. They've finally left school after 12 long years and it's something they want to celebrate. I think it's quite a nice tradition and I think it's important that they look nice. All my daughters got their dresses from TK Maxx. I always made it clear to them that their school proms don't warrant excessive expense."

For Lindsey, getting a dress she loved was more important than an inflated price tag. "My dress cost 50 and I got my shoes on sale for 12," she says. "To me it's about what looks nice, not how much things cost. I have some friends who have spent 250 on their dresses, and one of my friends is spending 500 in total. I suppose that for me to tell them how much my dress cost is a little embarrassing, but I think it looks great and that's all that matters. There's a Facebook group where you can describe your dress so that no-one ends up with anything too similar."

For many sixth-year pupils, their upcoming prom is an opportunity to behave like adults, treat themselves and go out in style. The "no expense spared" approach is routinely applied in much the same way as it is to a wedding. The irony of all that expense and effort is, of course, that most of the teens attending school proms in June 2010 will be cringing over the pictures of the evening come 2020, by which time there will be a whole new generation of wide-eyed youngsters flicking through Fiona Brown's rails of gowns trying to come to that most difficult of decisions: tulle or taffeta?