The Sun Dome Temples' insistence that all exchanges are denominated in gold ("the gold standard") is an indication of their less well-known but important roles as centres of banking and finance (and as secure, neutral treasuries for surrounding folk). Even the Sun Dome Temple in Prax. The vaults there contain various treasures from the Praxian tribes, some for safe-keeping, away from the covetous hands of other tribes, some as collateral for loans. Duke Raus of Rone also lodged the deeds to Weis Domain there, taking a large loan to hire mercenaries when the Lunar governor told him he no longer had any troops to spare for such an unimportant, far-flung outpost. (Raus's family heirloom the Wand of the Seven Phases is also said to be in the vault as further surety).
(I wrote this in response to post about Gloranthan economics on Facebook, so I figured I'd post here too - less ephemeral than FB if I ever want to come back to it)