Including custom functionality with multilingual capabilities from the start Imagine you have a global Drupal site with several languages. One market wants to add custom  functionality for just the English language. From a technical standpoint would it be better to develop the custom functionality with multilingual capabilities by default?

I understand this is a high-level question, but was wondering on the pros and cons. The custom functionality would fit well with other languages, so two specific questions are for instance:


Is the consideration of multilingual often more expensive than developing the monolingual version? 
On the long-term is it better to have the multilingual version from the start instead of adding it in a later phase? (updating code after functionality was pushed live).
Generally speaking, making a module ready for multilingual use is so incredibly easy when you're building it that it makes a LOT of sense to do it.   Retrofitting would be a real pain in the ass!  

I'm not exactly sure what module you're building, but it could be as simple as wrapping any user facing copy with t().