1 in 5 is certainly not uncommon by any reasonable interpretation of the term. 20% of the US is an absolutely massive market many could only dream to begin to address as a customer base.
That said, even that is not really all that useful. Anyone who is motivated can get these drugs for around $500-600/mo via programs that exist for the vast majority of the population. That roughly halves the cost comparisons here. Very few folks who want these drugs have zero options other than to pay full retail.
He didn't say 1 in 5 is common. He said 1 in 5 is not that uncommon. He's right. If 1 in 5 people in 1991 have a computer in the house, having a computer is not that uncommon.
This is a circular argument. In order for it not to be, you need to show how “having a computer in the house in 1991” is already a not uncommon thing for that to then apply to 1 in 5 not being uncommon.
That you perceive it as a complaint is hilariously ironic. I'm just telling you that your notions of "common" are wrong. You are attempting to use your economic situation to justify the outcomes for others. That, my friend, is poor posting.
> about 20% of households
This is super easy. 1 out of 5 is "not common." You can be as parsimonious as you like it doesn't change the ground reality that there are fewer people like you than there are people like you.
> How much more than one-in-five before a category of person is not uncommon?
Weird hill to die on. There's nothing wrong with or your economic situation except your expectation that other people share it. Which they generally don't.