What is Ivy League summer school like?

I am a freshman in high school and i have a 3.98 GPA, including an A in an AP class, and i am president of a school club. I am looking to get accepted into an Ivy, and I know that taking summer courses help. How difficult are they and are they worth it? Any answers appreciated.

What is Ivy League summer school like?
Ivy summer programs are:



1. Expensive (financial aid much less available than for actual college at an Ivy)



2. Often a mix of high school and college students. So, the curriculum is challenging, but it's not impossibly difficult.



3. Usually offer some of the same courses that the school offers in its regular college. The range of courses offered in the summer is not as wide, but the courses that are offered are usually the same as or similar to courses offered in the regular college.



4. Somewhat helpful to college admissions, especially if you get good grades. But it does not make you a shoo-in for college admission, nor would taking college classes in the summer necessarily be more helpful than some other meaningful summer experience (internship, community service, etc.). But it definitely beats watching TV all summer.



5. Expensive (did I mention that?)



6. Expensive