Most people would agree that internationalizing an existing app is more expensive than developing an internationalized app from scratch.
Is that really true? Or when you write an internationalized app from scratch the cost of doing I18N is just being amortized over multiple small assignments and nobody feels on his shoulders the whole weight of the internationalization task?
You can even claim that a mature app has many and many LOC that where deleted during the project's history, and that they don't need to be I18Ned if internationalization is made as an after thought, but would have been I18N if the project was internationalized from the very beggining.
So do you think a project starting today, must be internationalized, or can that decision be deferred to the future based on the success (or not) the software enjoys and the geographic distribution of the demand.
I am not talking about the ability to manipulate unicode data. That you have for free in most mainstream languages, databases and libraries. I am talking specifically of supporting your own software's user interface in multiple languages and locales.