Why don't you use pricelists feature? You can use different pricelists for different currencies and companies.
Price lists contain both fields that you are interested in: the specific company using this pricelist and the currency of the pricelist.
This way you will be selling the same product with the same ID and the same barcode in different companies with different financial results for your companies.
And don't worry, in Odoo the "Cost" field (standard_price) is company-specific. Accounting is also company-specific.
So consider the different pricelists.