S.D.
First, I love all of the creative suggestions here. Too bad mine are too old for these kinds of parties now. When they were having birthdays at this age, I remember trying to find party ideas that weren't so expensive. One frustrating thing about the home birthday parties was that the themed decorations, cups, plates, napkins and gift bags seemed to cost as much as having a party at Chuck E Cheese. So I quit buying those expensive party things just use plain or colored paper goods. One year my son had an alien party. We had black plates and let the kids put glow in the dark space stickers on them. I quit buying goody bags with all the trash toys in them, and would get a coloring book for each kid or something like that...one item that they will keep and use. Parents will love you for that! The dollar store is a great place for all of these items.