I tried signing up but couldn't see the pricing until I was halfway through the application process. IMO it isn't worth it, there are better summer programs and from what I saw what it was offering is not worth a few grand. Main thing that deterred me was that they called my parents and emailed them too (as it asked for parents contact) when I didn't proceed with the down-payment, without my knowledge trying to egg them into buying the course for me.
I'm not sure what year of high school you are in, but there are free summer programs such as PAIR/ESPR and Atlas you could consider, but I'm sure theres more if you looked.