Domestika has already started their Black Friday 2021 sales ahead of Black Friday with courses discounted up to 75%.
There's a huge variety of art courses on their website, e.g. digital and traditional, conceptual and techniques. Your favourite artists may be teaching there too. I've reviewed too many over the past few months.
The important thing to note is not all courses are in English. And I recommend getting the English courses because it's difficult to read subtitles and look at the art at the same time.