Hi nedski ,
Thanks for your post.
Which ATUM premium add-ons are you using?
FYI, prices are stored and shown in the site's original currency.
The supplier's currency is used in PO Pro to set the order's currency. If you update the Purchase Price from a PO in a distinct currency, the price will be converted to the site's currency before saving it.
If you want to show prices somewhere in the supplier's currency, some custom coding would be required.
Best Regards,
José Andrés