If you buy materials internationally, your suppliers may quote their prices in their local currency. Katana allows you to set Default purchase prices in your supplier's currency.
If there is no default supplier selected then the default purchase price is in your base currency.
If your purchase prices are in a foreign currency, you can see the prices in your base currency by clicking on the "i" icon.
The prices you set as default will be used on Purchase orders. When you set supplier currency and purchase prices, you can start buying in multiple currencies.