Maybe it varies for people, but I've usually seen a good friend step in, rent out a spot at a park, get some tablecloths and balloons and things to snack on. T

Maybe it varies for people, but I've usually seen a good friend step in, rent out a spot at a park, get some tablecloths and balloons and things to snack on. They're also starting to be more co-ed, too. If you go all out, maybe $100-$200.