[przemo_li]

If revenue they bring is estimated you may only need relative comparison.

After all if dev team days that more perspective project is very likely cheaper to make, why would you choose the other one?

See? No need for detailed answers if there is sufficient difference in qualities.

[emodendroket]

Relative comparison is exactly the scrum method which is why they don't estimate with time. And I don't think revenue estimation is any less subject to variance.