If they were being made today they would be considered very good quality violins and fetch in the $10,000+ range or more most likely, especially considering the location they are made in, the materials, and the methods employed to build them.
Classic literature is the same way. It's classic because of its influence, not just quality.
8 players chose a Strad as their favorite, so it's not as clear-cut as "new violins are better." It's more like, Strads are in a similar league, but do not outclass, new violins, despite costing an order of magnitude+ more. But then again, they are pieces of rare collectible art that are hundreds of year old–it's kind of amazing that you can play them at all!
So it's more like: imagine if there were a handful of surviving vintage audio cables from the 1600s (okay, the 1800s?) that performed almost as well as modern ones. I imagine they'd cost more money. And that wouldn't be so crazy, given their history.
Here's the original study & NYT coverage for reference:
https://doi.org/10.1073/pnas.1619443114
https://www.nytimes.com/2012/01/03/science/in-play-off-betwe...