Watch this video on Youtube:
Since this video was made the courses have developed quite a bit. Lots of improvements have been made to ESLinsider's best course - now called TEKA. And there's feedback and interaction on assignments which wasn't the case when this video was made.
Fast and cheap online TEFL sounds nice now, but you probably won't learn that much from it.
You can see:
Cheap and easy now is appealing if you just want a certificate to make it look like you know something but after you get there comes the work and if you don't know what you are doing you won't like teaching. Making an effort now will pay off later.
And you'll be looking for a new job before you know it.
Then again you have to consider your students.