The only way to really make any decent (for BsAs) money teaching English is if you have residency and can issue facturas. You can then market yourself to companies who need a factura to prove the expenditure to the tax authority (AFIP) and charge the same rates that institutes charge the companies (usually double what the teacher is paid) and get blocks of hours in one place. And, if you also speak spanish you can even earn better money because you can be a much more effective (and students appreciate it much more) when their ESL teacher can explain concepts to them that a monolingual person cannot (at least as clearly) e.g. - difference between blink and wink, how do you say "inside out, upside down, backwards, overturned", how do you explain (translate) "brand new", difference between broken and broken down, etc.