Feel free to use it. I wish I could claim ownership of that phrase. My father ran a used car dealership. He used to raise the price of some vehicles when certain people came in to buy a car. When I was a teenager I worked with him for a couple of years and asked him why he did that to certain people. He told me he had an eye for spotting people that could afford the "dumbass tax".
Stealing from myself from a few years ago:
One of the SomethingAwful guys came up with the following characterization a few years ago which I'll paraphrase:
"Bitcoin involves smart criminals, dumb Libertarians, and people of ambiguous intellect taking advantage of both."
...
Now, in 2016 and after the long anticipated (by me at least) so-called 'hack' of Bitfinished I'll suggest that those of us who are mainly whole and are still operational in this forum and under a stable persona tend to bin heavily into the last category. Perhaps I'm wrong, but it's the sense I get.
I'll admit to paying the 'dumbass tax' in most of transactions I've made involving vehicles over my life. When this has not been the case it has been mostly a result of dumb luck. Bitcoin and other financial sphere decisions have made it so that I can accept this form of tax when I choose to and when I want to focus on other priories.