You do get what you pay for... and I understand that there must be a balance between the course's price and the salary that you will receive in the country where you want to teach, but the course you take will dictate how much you will enjoy teaching and the quality of lessons that your students will get from you (In more competitive job markets, it will also dictate whether you actually get the job and the salary you'll receive).
Trinity and CELTA are the most regarded. A TESL Canada certificate is actually necessary to work in Canada and it's also highly regarded throughout the world. Take a look at Ontesol's 250-hour Specialized program. It's recognized by TESL Canada Professional Standard 2 and ACTDEC UK Level 3. This program is excellent for those who are interested in taking an advance course online (You do not need any teaching experience or prior TEFL/TESOL qualifications). A 20-hour practicum is also available for those who apply and it's actually required to obtain TESL Canada's accreditation. The program doesn't differ much, in terms of quality, from Coventry House International's Trinity CertTESOL course, but it's less expensive and you will not need to upgrade to a CELTA or Trinity if you take this course because this certificate is recognized everywhere in the UK, Canada, Australia, Dubai, Saudi Arabia, and the USA (in private schools).
If you are looking for an introductory course to get an entry level job, Ontesol also offers a 100-hour program, accredited by ACTDEC UK Level 1. Anybody who takes an 100-hour, or less, course online that is less than $400 and takes less than 3 weeks to complete will eventually need to take a more advance course in the next 1-3 years. http://www.study-at-coventry.comhttp://www.ontesol.com