Hi,
I am a native speaker, from Chile. I have a career in physics, currently writing my thesis. At the moment, I can only think in checking your Spanish, and if you may require more services this like research on local banks an policies this can be discuss later for both time and pay rate.
I think your proposal also include hiring personal for which I could translate from Spanish, although there should be a good number of English speakers available for such positions.
If I may, a word of advice - your description is a bit unclear, because for 20-30 USD I would only translate a few documents, yet you seek personnel for long term and I think freelancer.com offer also a choice to hire people under $/Hour rates, that may attract more bidders.
Regards,
Francisco