The days of a little pack of sweets, balloons and sponge cake wrapped in a tissue are long gone in the battle to ensure that children don't lose face in front of their young guests.
The demand for more upmarket trinkets means that hard-pressed parents now fork out on average more than 80 a time for party bags.
Parents find themselves competing to outdo each other in the quality of the bags' contents, with the average costing 7.48 and packed with model cars, plastic sunglasses and fake tiaras.
And with 11 child guests for every party this means an outlay of 82.28 a bash, the equivalent of 239 million a year across the UK, said the study for the supermarket giant Tesco.
Other items include Top Trump-style card games, water pistols, model aeroplanes, party streamers and temporary tattoo transfers.
The survey found demand for goodie bag contents had risen 12-fold in the past three years.
The average child attends ten parties of their own, so will build up a collection of plastic toys, books, games and other gifts but will also have to buy a present for each occasion.
Dr Pat Spungin, of the parenting website Raisingkids.co.uk, said: "Over the last year, I've noticed a growing trend from children to expect more and more in their party goodie bags.
"Parents need to plan a party that will appeal to their child's classmates whilst sticking to a budget - they should remember that a party is a celebration not a competition."
Janet Nicol, 41, from Edinburgh, a mother of two, said children were aware of what makes a good party bag. "You can't put any old tat in their bags, children are very discerning nowadays. But I always encourage my children to be very grateful for whatever they get," she said.
Mrs Nicol recently celebrated her daughter Natasha's seventh birthday with a party at a beauty salon.
She said, however, that she did not overdo it with the party bags: "Doing girls' bags is a lot easier than boys. I just buy lots of little things, like sparkly hair clips and other girly, fashion things. Just three or four items, some sweeties, a piece of cake and a little bottle of soapy bubbles. I don't think I spend more than 3 or 4 per bag.
"I think that children actually prefer the simple things. In the end, it's the parents that are making all these expensive choices."
In the United States, the one-upmanship over party presents has led to support websites being set up to help "moms and dads" competing with parents whose generosity sees them handing out bags more suited to an Oscar ceremony.
The support group Birthdays Without Pressure says one father gave out goodie bags worth more than 5,000 to guests at his daughter's 13th birthday party.