These were given out as part of the player/GM event where an Apocalypse Imperial Issue was returned to the Amarr in 2004. There were 20 signed copies handed to members of the corporations Ionstar and PIE. (The ordinary Pax Amarria is an npc tradegood).
Ten years after they were given out, it has been said that only 4 copies are found with active accounts. One is sitting in the collection of Entity.
There are no public records of any sales since 2005, but one Signed Pax was bought by Reality X in 2015.