Any comment on best practices for two companies with similar activities and business logic but with operating in different countries/currencies?  Related issue is that the price differences are not simple currency conversions, we charge more in one country than another calculated at an individual product level.  Any thoughts?

There is a third alternative: one instance and multiple databases. The proper way depends a lot on the business case and it needs a lot of knowledge and experience to find and deploy the most appropriate approach.

I have many years of experience with all 3 approaches, that's the reason for my statement.