Don't know where to post this, but under new Microsoft Store Policy (Point 10.8.7) it is now against their Policy to offer Krita against a payment on the Microsoft Store https://docs.microsoft.com/en-us/windows/uwp/publish/store-policies#108-financial-transactions
No it isn't against the new policy, since we the actual makers of the application, as long as the price is not extortionate, but reasonable. Given that closed source competitors are at least twice as expensive, I think the price is fine.