I taught in Bangkok in 2019. It was a great experience but I didn't think too much of the financial aspect. I had 3,000 USD (I'm American) in my bank account before I came. When I left, I had 1,000 USD left. Before I came, one blogger wrote that you will do fine with 1,000 USD in the bank. Totally wrong.
What most travel bloggers dont talk about is the cost to be legally working in Thailand. Most schools don't pay the cost. Visiting immigration, border runs, transportation cost, picture fees, application fees, police clearance fees, work permit fees, etc... If you get scammed by your school and decide to stay in Thailand, you have even more additional costs. You have to find a hotel/hostel and stay for a few weeks to a few months and you're not getting paid for a few months while you find another job. If you can't find a job in 30 days, you have to do another visa run which is an additional cost. These costs mount up. I don't regret living in Bangkok but there are hundreds of costs you won't find out until later, and they can make and break you.