Just my 2 cents. Initially I thought, why no upgrade pricing for existing V1 customers. I bought Photo through the Apple store in 2015 I think and then Designer and Publisher on their website so they could save the Apple charge. I also bought the 3 books accompanying it, in 2020-2021. Good resources.
But I understand their reasoning about pricing, and why should I want a deeper discount or be jealous that a new customer gets a good price? For the suite price of ca. EUR 119 you get good apps on your iPad too, that will last you quite a few years. I will purchase it this week on their website again, to save the Apple charge.
If they want to do something extra for V1 users, a free upgrade to the book with the new features would be appreciated. Like a free PDF or else only charge a shipping fee plus small markup for the updated books.