Intent doesn't really make sense as a basis for ethics. If I do something that will result in someone's death, and I am aware of that, but I do it because I want some material gain, is that wrong, even though my intent is not for the person to die? Morality should be based on what you expect will happen, as opposed to your reasons for doing something.
A virtue ethics supporter would look at all their thought process, not just their desired end goal, to judge them. So they'd say that was immoral due to them not valuing a person's life over material gain. Finding a person's life an acceptable cost is
part of their intent, and thus can be ethically judged.
EDIT: I'll rant about it since it's my view:
Virtue ethics takes all morality out of actions themselves, and instead places moral responsibility entire on a person's character (or their "virtues"). A person's actions are not inherently good or bad, but by observing their actions, you can see evidence of their inner character, and thus judge their morality.
So, a virtue ethics supporter would not see a difference between attempted murder and murder. The inner character of the person who attempted it is the same, but in one situation, something got in their way and prevented their goal. That outside influence should not have an effect on how they are judged.
The problem with this moral theory is defining the virtues that should be espoused. What is considered a "good" inner character to one person could be a "bad" inner character to another. As I'm a supporter of subjective morality, this isn't a problem to me, since we can then all decide what virtues are good for us (as that's what we do
anyway).
As for quantifying benefit, you can absolutely do it in situations where it's lives being compared to one another, with more sentients being more valuable. Since in our society, money can unfortunately be equated into saved lives, wouldn't the value of a human's life simply be the monetary value of the items necessary to keep them alive and productive their entire remaining life(or expected life), plus the amount they will produce over their lifespan? If fifty million dollars will sustain 20 families for their entire lives, then it should be right to kill someone who doesn't produce anything for society for that amount of money.(Assuming that the murderer donates all the money to those families) Ultimately, more productive lives with a decent standard of living is better.
Thing is, you'll never find a set scale that everyone agrees on. You'll come up with wacky stuff like
this. Utilitarians don't really have a problem with that, but supporters of other ethical theories will scoff.
I mentioned deontology before, so I'll expound on what they think too: Morality is entirely action based and objective. Stealing is stealing, essentially. So taking a loaf of bread to feed one's starving family would not justify the theft; they're still guilty of it no matter their intent, no matter the consequence.