If you do iterative and lean development, localizing using freelancers website will really slow down your release cycle. This multiplies your fixed costs you spent running your small company.
Another point, you'll also need to pay others skilled translators to verify the quality o the localization.
In my case, after localizing it, the numbers of user increase just a few. If I would spent this money on marketing and development, I'm sure that I could get better results.