Honestly, I think Christie's has an interest in their estimates being semi-accurate, but not _too_ accurate. They obviously want to be within an order of magnit

Honestly, I think Christie's has an interest in their estimates being semi-accurate, but not _too_ accurate. They obviously want to be within an order of magnitude so they don't look stupid, but overestimating might drive up the price and make them money. Also, when things sell for double or triple the estimate, it makes the news, with Christie's name right beside. Someone else said Sotheby's bought a database of art prices for 7 figures - why wouldn't a bunch of headlines with their name be worth a few million to them? Additionally I think they have an interest in prices being as high as possible normally, with estimates high to encourage that. So the pattern would look like: Antique Japanese woodcarving, $10MM predicted -> $12MM public predicted Set of documents from Roman times, $5MM predicted -> $6MM public predicted Van Gogh paintings (aka more headline potential), $10MM predicted -> $3MM public predicted Then you get the headlines "Van Gogh paintings fetch more than triple the estimate at Christie's auction", which is free PR for Christie's.