I've taken the TEFL course and am currently teaching English. While my experience may differ from many people, I considered my 4 week TEFL course to be, for the most part, a waste of time and money. I admit that having a few practice classes helps prepare you for your first private students, but instead of paying $1,200-1,500 dollars for TEFL, you might as well offer a few free classes to your first few students until you can get the hang of things.
It may be more difficult to find work without the TEFL certificate, but if you have a good knowledge of the rules of English grammar, and a degree, then a TEFL degree does little if anything to make you more qualified. My class consisted of 8 people, and it was a general consensus that the best thing about the course was that you met other people in a similar situation, not the actual content of the course.