I18n and going global early on

This weekend I spent a decent amount of time adding language support across 4 different audiences (English, Spanish, French, Arabic) to Stylized. We've been seeing a lot of traffic coming in from overseas and I'm wondering what the playbook looks like for adding internationalization support.

Is this something people do early on in their products in order to keep the growth going? The obvious downside for me is that it adds that much more overhead to new features, as well as making the manual QA matrix explode. Also, there are some countries that just aren't as wealthy and so their users won't really be paying customers.

Any suggestions for us? How much support should we offer to international users, and is this a problem worth thinking about?