Sure, if you don't have a job you are willing to work for less. With 3000 S$/month you wouldn't make a great life in Singapore. An average worker makes about that.
But Tiger is definetly not a low wage airline. Together with the flight pay you earn as much as someone in SIA or SLK. Without the benefits and the bonuses though.
Commuting from Johor Bahru is a bit tricky. There is this causeway and sometimes you wait an hour or two. There are in fact workers who do it. But you really loose time. And from the causeway it's another hour to Changi.
Dani