There's normally a big difference between your 35-40k teachers and your 70k+ with benefits lot.
I did the crappy 35-40k jobs years ago. These positions are typically filled by three types of teachers;
1) Your young and carefree teacher who'll do a year or two at most. They are here for a working holiday and spend all their money on holidaying and partying. God bless this lot. They're doing it right.
2) Your stagnant teacher (often good teachers who kinda get stuck in a rut and think there isn't anything better out there) These are the good guys who just need to be more assertive.
3) And then there's your last-resort teacher (the one that had to be employed otherwise the kids wouldn't have a teacher at all, or more importantly for the school or agency is they wouldn't make their money).
They're drifters and outlaws (some literally are on the run from the cops). These guys are the legends of TEFL. They've given me so many stories to tell over the years. Stories ranging from a teacher who wore a shirt and tie with tracksuit bottoms and brogues because he didn't do his laundry, to a teacher getting stabbed by his partner after he got caught cheating with a Nana ladyboy. You would see these teachers around school (when they showed up) and you knew you weren't doing too bad.
Once you go into your 70k+ with benefit jobs (I use this as a reference to my first proper teaching job) it becomes quite boring. The young teachers take it very seriously as it's their career and they want to impress. The stagnant teachers aren't really stagnating. They've just got older and want the quiet life. And the last-resort teachers don't exist. They simply would never be employed as they have no place inside any school or near children.