Teaching jobs

Does anyone know how difficult it would be to get a teaching job at one of the English-speaking schools around San Jose?  I have good qualifications, but I'm not sure what sorts of certificates are necessary.  Also, assuming it's at least possible, does anyone know if the pay is any good?  Thanks.

I taught at Politecnico for three months, generally they all want a tesol. the pay is pretty low...I was only getting $900 a month and food is expensive

What is a tesol?

Its a certificate for teaching ESL students. Usually they prefer an inclass program which takes a month and can cost up to a grand us money, good thing is it never expires