Stanford OSHX Post-AP Math/Physics Classes

I’m a rising junior who has already taken both AP Physics C and BC Calculus and I recently got an email from Stanford about taking online classes in Light and Heat and Multivariable Calculus. Has anyone taken these classes in the past and if so what were your thoughts about it/would you recommend it. The classes are really expensive ($1500/class) so I want to make sure it’s a good class before putting down that much cash.

The link to the program is : https://ohsx.stanford.edu/