Which corporation makes the "canned" courses?
And what do you mean by "homemade" courses?
AP History was created by a subsidiary of McMillan called Bedford St. Martin's. CTY was also looking at in-licensing a number of courses from an online education company. can't remember its name now. The courses were made for at-risk students, not gifted students. This is the problem with an in-licensed course: it isn't made with gifted kids in mind and therefore may not meet their needs.
The homemade courses tend to be made specifically for CTY. Crafting the Essay is an example of one of these courses.
Thanks. We're using k12.com courses through a public virtual school. These courses are not designed for gifted students, but they are compactible so it's easy to accelerate. The lessons usually clearly identify what's review, repetition, extra practice, etc., so you can skip through without much risk of accidentally skipping new material. But it's free for us, so the price is right, it can be made to work for gifted students, and it beats our otherwise appaling options here.
But, I would not pay good money for these courses. If CTY (or EPGY) are charging large money for these type of courses, then it's not worth it, and personally I would pass. It's only worth paying for courses aimed specifically at the top students meaning they have chosen to shrink their market by at least 90%.
