Every parent loves a school photo of their kids looking smart in their uniform.
But the cost of that new jumper, blazer, skirt or tie have forced many families to conclude that the maths just don't add up.
Mums and dads have complained of being unable to cut costs by shopping around as they find themselves tied in to a single supplier, either their school or a nominated retailer, adding £10 or more to high street and supermarket prices.
The Office of Fair Trading claimed the average price of a secondary school sweatshirt sold under restrictive arrangements was £12, against £8 at competing retailers and £5 in a supermarket chain.
The body said the tie-in effectively acted as a "tax" on families.
And it claimed parents could also save hundreds of pounds if schools removed strict restrictions on what pupils should wear.
Susan Oxley, assistant director of the OFT's goods and consumer group, said schools could still have smart school uniform policies without appointing a single supplier.
"Schools could achieve consistency through setting out colour and style requirements in more detail but still allow parents choice about where to buy uniform items," she said.
"When schools require that uniforms are bought from a preferred supplier or shop it can act as a tax on families, which mostly goes to the chosen retailers.
"However, when families are able to shop around for school uniform items it can drive competition and bring down prices for all.
"We know schools don't want families to be left out of pocket."
A recent poll revealed mums and dads in Birmingham spent an average of £1,400 per year on education, including £160 on uniforms, £247 on meals, £182 on travel and £143 on back to school supplies.
Other costly items included an average of £117 on school trips, £69 per pupil on sports lessons and £68 spent on school clubs.
Birmingham Citizen's Advice Bureau launched its 'Adding Up' campaign after seeing many parents and carers struggle with the hidden costs of sending their children to school.
A spokeswoman said: "We would encourage schools and education authorities to promote cost-cutting policies on school uniforms, trips, kit and other items.
"This could save families hundreds of pounds a year
"We need to make life as affordable as possible for parents and carers, many of whom are already struggling due to the rising cost of living and cuts in welfare benefits."
Those concerns were echoed by Rednal-based NASUWT, the largest teachers' union.
It warned some less well-off families could effectively find themselves barred from their first choice school because of the costs involved.
"It won't be long before some parents find the cost of school uniform, activities and equipment puts admission to the school of their choice way beyond their financial means," a spokesman said.
"The fundamental principle of a public service being free at the point of use is being contaminated."