For example, I would like to add the following columns to help us prioritize :

"Business Value"

and a custom column

"T-shirt size" that acts as a first estimate, made by non-developers (probably product owner).

And a final column

"Estimated Priority"

Which is simply a multiplication of the first two. This way, the Product Owner can more easily spot quick wins : Small Estimation x Large Business Value or things we probably won't do : Large Estimation x Small Business Value.