Hello Avixy, we currently don't have any type of key or access asset that offers a one-time purchase with lifetime updates.
We are planning to release one soon, I will message you when it’s available.
I also purchased the mega bundle before this was released but this was so good that i purchased this separately just because it is so good and to support you guys. However, in the future, it would be great if those who previously purchased this bundle could receive these new content for free or at a special discount.