Another one who grew up in the 80s, never did we have to pay to attend a party, whether it was macca's or Luna park. In our family if you say its a party you supply the food drinks, nibbles and a cake. It doesn't have to be fancy for goodness sakes.
I am of the opinion if you can't afford the above then you really shouldn't be putting on a party.
I guess we also didn't have a party every year and neither did our friends. I think a lot of parents think a large party every year is a pre requisite these days and somehow there child will be damaged without an official party.