last time I came to Thailand during covid, I stayed almost 8 months. After the first 60 days on tourist visa, I got a 30 day visa extension. Then I got 60 day Covid extension 3 times for 1900baht. In another forum, they said they are still doing it, but the program ends July 25th. (they are likely to extend the program by two more months, as they have kept the program going two months at a time since the start of covid).
I was there when covid started, in koh lanta. $400 /month got you an ok beach front hotel with weekly cleaning and AC. You could cook your own food for less than $50/month if you want to live a bit frugal, but still get full. A bike rental was $30/month. Sounds like an amazing time. Nothing else really to spend money on then 😅