Bruce,
I dunno if they're dangerous or not. Have fired a lot of Sakos with "Sako" extractors over the decades, as well as other rifles with similar designs, without a problem.
I've never had the job done, partly because I've never had a 700/722 extractor break in at least 100,000 rounds fired. But have heard prices start at around $125.
MD,
That's about what I paid 3 years ago to have a Sako extractor put in a 300sav just before deer season. The old extractor wasn't "broken" just worn to where it wasn't doing its job.
Mike,
I would have paid that for it in a heartbeat, and then taken the heat when I got home 😀