Really? What are kids parties like these days?
I seem to remember having simple parties when I was a kid: just a load of kids running around the garden and playing games, then party food and cake at the end. Occasionally we would go somewhere like a 'Softland Play' at a local leisure centre, or when we were older, a day out at a wildlife park or something, but nothing more elaborate than that.
Most parties my daughter attends are ~£20 per child with no cake or party bag (parents still do those). Soft play is very popular for her age. She has had a farm party, Pizza Express party, and a few hired halls. Only one party at someone's house! Which was bar far my favourite. The kids had a ball!
I think friends in the US are spending just as much money due to the Pinterest craze.
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At least the parties are home based though. I hate "keeping up with the joneses". Not my style!