Stop me if I'm wrong, this is how I'm figuring it.

Assuming the 5* rate for the 80 roll banner is 0.4%, the probability of going the full 80 rolls for a 5* is (100%-0.4% = 99.6%)^79
= 0.72859759854
Assuming the 5* rate for the 110 roll banner is 0.2%, the probability of going the full 110 rolls for a 5* is (100-0.2% = 99.8%)^109
= 0.80394992739
This does not factor in soft pity.

So there's a roughly 80% chance I have to max out the 110 roll for a 5* (which is guaranteed to be what I want) and a 72% chance I have to max out an 80 roll for a 5*, which has a 50% chance to be what I want.

80 1 110 1
80 0 110 1
80 1 110 1
80 0 110 1
80 1 110 1
80 0 110 1
80 1 110 1
80 0
80 1
80 0
80 1
80 0
80 1

1040 6 770 7

This assumes I'm hard pitying everything of course, and if I'm really doing that, there is an argument to go 50/50 anyway because I'll get Awareness for the standards and other whale tear benefits. However, going for 110 will help me progress 4*s faster, though I'm not sure how relevant that is.