Those 2 weapons are the rarest tradeable items in the whole game. ( After unusual hats )
They go about 40e each atm, but they will get extremely expensive in the future, since only about 160 people have those.
Why is it so rare? That's because you had five days to craft one of those weapons from tokens. For Fan O' War, it was 1/7 chance to craft it, and it was dropable so people got them randomly without crafting. But only the ones that were crafted turned Vintage. Exacly same for Concheror, except 1/3 chance to craft it. That's why Vintage Fan O' War is about 0.01% rarer.
Added (2011-09-17, 8:39 Am) --------------------------------------------- By new TF2 items scan, only 0.05% of all TF2 players have Vintage concheror. 0.10% have Vintage Fan O' War!