I've read so many doom and gloom letters and posts about the perils of being over 50 and a teacher in Thailand. I teach in a provincial private school an hour out of Bangkok. I also run some courses at the local university as well as teaching IELTS preparation courses at a leading academic language school. Total hours 35 per week, total pay 96,000 per month excluding bonuses ( before you say that's too many hours, I used to work 60 hours a week in a high pressure job before I came to Thailand 7 years ago).
I'm 60 and have never been in so much demand. Am I that special? Not at all. I'm just proactive and do a good job. By the way, at the language school there are four out of the six teachers who are over 60. It certainly helps though that I have a lot of experience coupled with a Masters degree. My advice to the older guys, if you are qualified there is a lot of work. You just have to get out there and sell yourself. if you are armed with just a TEFL, of course you will struggle as you are competing with a veritable army of young good looking and likewise unqualified teachers. One final piece of advice, have your feet firmly placed in at least a couple of camps, that way if one source of your income suddenly dries up you will still be OK.