As long as work is interesting.
I lived in Bangkok on less than 40,000 when I first arrived, and then later on a bit more than 40,000, and occasionally much more. For me, living in Bangkok on 40,000 (or less) was a pretty good life, but making more than that was better and making multiple times 40,000 was even better yet (but not multiple times better). But other readers might have had different experiences or have different viewpoints.
Personal opinion, as long as the work is interesting and your personal life is OK, making a decent salary is important, but having a high salary less so. Why not try to eventually have interesting work, a good personal life AND a bit more than an average income. It doesn't seem an impossible goal over one's lifetime.
Jack
