Well...market and gifts are bassically all that is left
There are bountys and the double it button...idk if there is more.
It is doable. For 200kish you can request something like that.
You could write a script that actively reads someone's transaction history, it isn't that hard to figure out how much someone makes on market and in gifts.
I don't personally have the time, and though I know it is easy, I do not know how to do it. I just know there are simple ways to do these things, I haven't really coded enough.
I don't see the usefulness of this feature at all, and no one had gone over why it would be useful to the community.