Okay, mine is very easy. Pixel 7.
You misunderstood. If you already choose e.g. monthly Ultra, there is no option to change for the one-time option or to the yearly subscription. You cannot change it, just with cancelling your already active subscription and go with another option.
But I think it’s a limitation of the Play Store but I’m not sure.
I interpreted enough as really enough, when you are really well off and can afford the good stuff/vacations/good cars whatever.
But you are right. The definition of enough changes through ones lifetime quite a bit. I would have a really hard time going back to broke (student).