What makes one meteorite more valuable than another?
Rarity of type, whether it was a witnessed fall, freshness, beauty, historic importance, size and shape, an official classification and trustworthy, legal provenance all raise value. Weathering, damage, doubts over origin or missing paperwork lower it.
Two meteorites of the same weight can differ hugely in value, and the reasons are surprisingly easy to understand once you know what collectors and scientists care about. Rarity comes first. Ordinary chondrites make up the vast majority of known meteorites and are found by the thousand in deserts. Some other groups, such as certain unusual achondrites or rare carbonaceous chondrites, are known from only a few stones. Meteorites from the Moon and Mars are also scarce compared with ordinary stones. The fewer pieces exist, the more people compete for them.
Story matters too. A witnessed fall, seen arriving and collected soon after, is fresher and has a known date and place, so it is generally prized above a find of the same type. Falls with famous histories, such as Ensisheim in 1492 or L'Aigle in 1803, carry extra appeal. So do meteorites that struck something, like a house or car.
Condition and beauty count. Collectors look for fresh, intact fusion crust, smooth regmaglypts, oriented cone shapes or, on iron meteorites, a striking etched Widmanstätten pattern. Rust, cracks, cutting damage or heavy cleaning reduce appeal. A complete individual stone is often treated differently from a broken fragment or a slice.
Documentation and legality underpin all of this. An official name and classification published by the Meteoritical Society, a clear record of where and how the meteorite was found, and confidence that it was collected and exported legally all matter. Specimens from places where collecting or export is restricted can carry legal risk. Without trustworthy paperwork, even a genuine meteorite is harder to sell. Remember that markets change, so value is never guaranteed.