Have you thought of a bowling party? Fun for kids and adults. You get two lanes and the little kiddos get the bumpers that go in the gutters so that their ball will hit the pins and they feel so grown up.
Our local bowling alley has parties for 10 people for $60. You all get to bowl, the shoe rental and a slice of pizza and a coke. You just bring the cake and any plates and decorations you want to use. They also have a rollerskating rink attached. A party there is slightly higher priced. Just a thought. Hope it helps.