MY birthday challenge- The $ 100 birthday party

So I have two birthday parties coming up next month. My daughters are turning 9 and 4
they are just one day apart 13th and 14th!!Throwing one birthday party can be stressful
but two is insane! Lot of people ask me why I don't have a combined party for the two?
The problem is that my nine year old has nothing in common with the 4 year old, they have very different likes & dislikes. The 4 year old is a lil princess and miss preteen has long outgrown all things princess,and thinks its totally uncool!!
I believe a birthday is a celebration of the individual.and the party should reflect the child's personality.
Challenge # 1
The Princess's Castle party was a no brainer
I am building a Castle out of cardboard boxes
Challenge #2
The preteen party was s challenge. We had all but decided on a hiking trip with a picnic but realized that its rainy season here in California and doing anything outdoors is risky.My daughter suggested they do a Broadway style play at home!
Now I thought that was a neat Idea. So we are doing the Lion King.
All the guests get to dress up as the animals characters.We will set up a stage and they get a chance to sing dance and perform a mini play.

The Real challenge is this year, well I don't want to do a over the top party like I usually do.
This year I am setting a budget of $100 for each party. So lets see if I can throw a
fancy birthday party for under $100!!!