Hi, Monique! The good news is that the 'Ohana breakfast is an all you care to eat meal, served family style. You may be able to get away with skipping lunch that day, opting instead for just a lighter snack. That will help save you a little bit of money right there!
Some more good news is that children age two and under do not have to pay to eat at the breakfast. There will be plenty of food for them served to your table, but children of this age are generally thought to not eat very much, so there is no charge for them.
The meal will run you about $25 for each adult, and for children between the ages of three and nine, the cost is about $14. The cost includes unlimited orange juice, milk, and coffee, so you shouldn't have to worry about any additional charges for drinks.
Again, this is served family style, so they will bring platters to your table, but whatever you run out of or want more of, just ask. They have always been happy to replenish items that my kids find tastier than others!
Have a great vacation!