Sigh, as usual we don't have anyone with real experience on the topic. Let's speculate further then

When you decide on multilanguage game you need to cover these:
- code supporting multiple languages (one time only)
- translation of the game text & help files, you also need to maintain these (per language)
- staff speaking the language (per language)
- ability to make local promotion - votesites, SEO, etc (per language)
- implementing local payment options - you can not expect everyone to use PayPal (per language)
To me the last two are the most tricky, because it is hard to outsource these (especialy with limited funds). How can you promote the game if you don't speak the language? How can you understand the local recuirements (like payments methods prefered in that country)? You will need to register on various sites, register and use local services, need to analyse kewords for SEO... Quite challenging without the understanding of the language

As for number of languages, I'm not sure if it is worth implementing only 2. The overhead caused by the multilanguage code seems quite big, especially for a young game with rapid changes. I can not imagine making changes to language files when you release like 4-8 updates a week, which is quite reasonable volume for a brand new game... I would go for 4-6 languages (so definitely not only those that you speak yourself) to make it worth the additional hassle.
I was thinking about something like that for myself: A simple game with not much text. Developed in English and the development stopped quite soon after release and playable game. Then, rewrite it to support multilanguage. Next ask community (or hire someone) to prepare language files. Next setup several different games (per language, 100% independent, using different national domains for better SEO). After that setup some staff. Then comes the tricky part, need to promote the game and create payment system (I assume I do not need to learn the language since it does not make sense in a long run...).
Hmmm, it does not looks very encouraging so far, writing a new best selling hit in English only sounds so much easier to me