How much does it really have to prevent one of the most painful and expensive forms of cancer, not just for you but also your family, to justify $7/mo? Not very much, in my book.
Same comment as the one above. There are literally infinite things you can do to reduce your risk of mortality. This would have to be among the best options if those things.
If you have a radon test indicating there's a problem, then it is no longer theoretical. There aren't an infinite number of pressing and known risks.
I think it's a mistake to conflate an infinite number of hypothetical risks with a definite and known risk. It leads to analysis paralysis and FUD. It is not possible to know what, among all of the infinite hypothetical options, is the best to reduce your mortality. So let's focus on the concrete steps we can take and that we do know are effective.
For most people, that is not radon mitigation, because most people don't have a radon problem. If you find out that it is a problem for you, and you have the cash to solve it - just solve it. It's that simple.
