Teaching in Thailand is a joke. Most of the things pulling you here can be found in other South East Asian countries. For what many of these so-called 'international' schools are offering, in terms of salary, a non-degree holder could likely achieve in countries such as Vietnam.
Many schools in Thailand simply don't respect foreign teachers (of any nationality) and contracts are meaningless and frequently dishonoured. You don't even want to try bothering with these 30-40k jobs, especially in Bangkok. If you choose to, consider that they may not pay for your holidays and likely don't provide any meaningful health insurance. In addition, I have found that you often need to budget for materials, if you wish to make your classes interesting/ enjoyable.
After arriving with no degree and no experience, 8 years ago, I now earn about 100 pounds a month more than I did then. This is having gained a BA in TESOL and an M.Ed. Take it with a shovel of salt when people claim that gaining education qualifications will turn your fortunes around in Thailand. The reality for myself, and many other teachers I know, is that you put in a shift at school (hybrid learning and clown world goof rules) and then have to go home and do 2-3 hours of online teaching or you're living hand to mouth. Have a good read through the letters on Ajarn, to get a feel for the situation, and just look at the qualifications the job ads are demanding in return for what they're offering. In short, do your research before coming here. I'm on my way out.