I'm not sure which one of us you're referring to, but the primary "cost" as I see it is disclosing your DNA to some 3rd party, who are then free to use that DNA, or sell it, or whatever as they like.
So, in a sense, if you use a DNA service you are essentially putting your unique DNA marker "into the world", and it can be identified to you (especially if any of our relations have also been tested.)
While there may not be any immediate implications, that DNA might be used by law enforcement, insurance companies, employers etc (either now or in the future.) So there are potentially "high costs" - we just don't know what they are yet. But this bell cannot be unrung.
Balancing this possible harm are the possible benefits. Personally, I don't really see any compelling benefits, but my goal with this reply to the original question was to determine if I was missing something.
So, in a sense, if you use a DNA service you are essentially putting your unique DNA marker "into the world", and it can be identified to you (especially if any of our relations have also been tested.)
While there may not be any immediate implications, that DNA might be used by law enforcement, insurance companies, employers etc (either now or in the future.) So there are potentially "high costs" - we just don't know what they are yet. But this bell cannot be unrung.
Balancing this possible harm are the possible benefits. Personally, I don't really see any compelling benefits, but my goal with this reply to the original question was to determine if I was missing something.