I am not sure what the pay package is now. I was there in 1996-1997. I worked for Sempati Airlines. Pay was around $4500 USD per month. Capts made quite a bit more. I went through a UK contract agency--Strongfield Aviation.
Cost of living depends on where/how you want to live. If you want the expat experience then it will cost more. If you live a bit like the locals then its a lot cheaper. I had a studio "expat" apartment in Jakarta--It cost around $1000/month.