This is a great question, I am rethreading it!
I am not sure yet, I have already subscribed for 10$ today, and I have only 14 HBD left, so if I consume all of that - I should wait to earn more.
For now, I think I will stick to app 2,3 but this may increase over time. I wish I could sub to all, and hope that more tiers will be available soon!