We have a similar issue in our basement, found, after I got the property of my dreams and a nice home on it. So....I'm gambling that it will wait 25 or so years before it sneaks up on me!
Good Luck with whatever you decide! memtb
Thanks!
In your case I'd just get a mitigation system installed.
While we've passed on the house, I think likely if we find it in the next house we're interested in — which I think likely — we will by then have come to accept it as something one should mitigate and then monitor.
The next place we buy will be the fifth house we've purchased over the past 20 years. Radon never came up one way or another when buying our place in Japan, nor did it for the three houses we've bought in Hawaii.
Here in Oregon, Portland, it came up when we bought our condo, a two floor townhouse in a wooden building with four other condos, but the place passed the radon test.
So this was our first experience with it as an issue.
My wife talked to her sister in Michigan who explained they have a mitigation system in their home, and monitor it by testing every three years. I suspect my wife will come around to accepting it in time.
The place we were looking to buy ticked off most of our requirements and was a good deal, but the transaction timing was earlier than ideal. Eight months to a year or so from now would work out better for us anyway.
(Plus, looking for houses gives my wife something to do!

)
That EPA brochure that 6518John linked to is a very good place to start to get the basic facts for anyone interested in understanding the issue. (The EPA says it should be mitigated if 4.0 or above, but that mitigation is simple.)
Really do appreciate all the varied viewpoints, experiences, and opinions. Quite helpful for us.