The add-on allows you to configure the main and secondary currencies for each storefront language and automatically switch price display when the language changes.
Purpose
The add-on solves the multi-currency and multi-language task: for each language you can set a main currency (e.g. RUB for Russian, USD for English) and optionally a secondary currency for display in parentheses.
How it works
The add-on adds two columns to the languages table: ms_default_currency_code (main currency) and ms_secondary_currency_code (secondary). When displaying prices on the storefront, the overridden common/price.tpl template is used. Depending on the "Switch currency automatically" setting and the selected language, prices are displayed in the corresponding currency.
With automatic currency switching enabled, when loading a page without an explicitly selected currency in the URL, the currency corresponding to the current language is used. A JavaScript hook updates the selected currency display in the panel.
Location in admin panel
Add-on settings: Administration → Add-ons → Add-on management → ms_price_change.
Currency settings per language: Administration → Languages → Languages — for each language set "MS: primary currency" and "MS: secondary currency" fields.