These Stones contain lots of organic matter and water, they will degrade quickly on earth. I suspect that research on these objects is very rare to have such a fresh sample. Probably it does not have this value because of rare metals or something, however because of its freshness has tremendous research value.
My understanding is meteorites have potentially high value because they're increasingly viewed as equivalent to samples collected from foreign planets/asteroids. Viewed through that lens, the value competes with the cost of retrieving a sample from wherever the meteorite formed.
