I was reading the original comment thread on Torture vs. Dust Specks, and notice Eliezer saying he wouldn't pay a penny to avoid a single dust speck - which confused me, until I noticed that the original specification of the problem says the dust speck "floated into your eye and irritated it just a little, for a fraction of a second, barely enough to make you notice before you blink and wipe away the dust speck." I guess I blanked that out when I first read the post. My default visualization when I imagine "dust speck in my eye" is something substantially more annoying than that.
This leads me to wonder if people would have responded differently if instead of going out of his way to make the alternative to torture involve something as trivial-sounding as possible, Eliezer had gone for some merely minor mishap - say, getting shampoo in your eye. After all, lots of us have gotten shampoo in our eyes at least once (maybe when we were kids), and it's easy to imagine paying $2.99 for a bottle of won't-irritate-your-eyes shampoo over an otherwise identical $2.98 bottle that will hurt if you get it in your eyes (or your kid's eyes, if you're totally confident that, as an adult, you'll be able to keep shampoo out of your eyes).
From there, it's easy to argue that if you're honest with yourself you wouldn't pay $(3^^^3/100) to save one person from being tortured for 50 years, so you should choose one person getting tortured for 50 years over 3^^^3 people getting shampoo (the stingy kind) in their eyes. I suppose, however, that might not change your answer to torture vs. specks if you think there's a qualitative difference between the speck (as originally specified by Eliezer) and getting shampoo in your eye.
We're comparing two values specifically here; torture vs minor annoyances. In that case, then yes, I would rather spend X money preventing someone from being tortured then spend the same X money protecting people from getting dust in their eye. The values, IHMO, are on fundamentally different levels.
Now, if it was "torture vs. saving lives", or something like that, then maybe you could do the math.
It's basically the same argument as the classic "how many people have to enjoy watching a gladiatorial combat on TV in order to morally justify forcing two people to fight for the death?" I don't think you can do that math, because the values (enjoying watching a tv show vs. human life) are on fundamentally different levels.