And not only people that work in companies of the valley, for example, Google Brazil can pay here less than they pay in the valley, and other companies here end paying less than google pay, the result for example, is me. (I get 16k USD year, and I earn more than the average programmer here).
USD 26k to 37k is a common range for senior developers in my employer. And I'm not counting "13 salary", bonuses, overtime pay, health and dental care.
I doubt the average is less than 16k.
The highest I was paid was 5k BRL as contractor (no 13, bonuses, overtime, etc...) and back then I was one of the highest paid persons of the company (that had about 50 programmers). I remember talking to other people and lots of people except DBAs and exotic language specialists working on IBM had also similar pays.
apinfo.com.br salary survey matches my experience for average salary. BRL 5k is an average salary for a senior developer. I was making BRL 4k after I graduated from UFRJ about five years ago.
A senior specialist (band 8) working for IBM earns way more than that, plus benefits.