How much average wage in Singapore?

Hello Pangki Sudirjo.

Welcome to Expat.com!

In meantime, do not hesitate to read the threads on Cost of living in Singapore.

Thank you,
Aurélie

http://www.numbeo.com/cost-of-living gives a very good (and usually accurate) cost of living comparison.
Usual starting pay for a fresh graduate in your field is S$3000/month. I don't know how much increase you can get with 3 years experience.
Average household income in Singapore is S$5600/month.
Since you'll be renting, you need more than the locals (who generally don't rent).

Hi beppi
nice to talk with you again

I'm not the luxury one actually
Indonesia is a great place and have a kind of people but however it's not an easy place. I can live in the horrible situation, but I will be there with my girlfriend

I was googling and found S$650 apartment rent with complete furniture. is that true? if that's true, I think I'll take it.
I'm not drink beer, nor smoking, but I like to taste a wine
however I just do it once a month, both of us do it...

my girl have 5 years work experience in restaurant and hotel hospitality industry, do you think a lot of opportunity that she can do in that place?

I loved to work in Finance & Banking Industry, that's match with my background, even though I can do job with not really far relevant with my background

that's it
anyway beppy
give my ward regard for your daughter

I mean "warm regard"

Apartments cost at least S$2000/month now.
If you are o.k. with just a room, and sharing the rest of the apartment with others, then you can find something reasonable for S$800-1000/month, a bit more with attached (private) bathroom.
For S$650/month, it can only be a small room far from food and public transport, with shared bath, no aircon and no cooking allowed. Even then it's still a good price!

Wine in shops costs at least S$20/bottle, or S$30 for a more drinkable one. In restaurants it's at least S$60/bottle, S$100 for the drinkable kind.

The hospitality industry is booming, which is good news for your girlfriend. She should apply at the new resorts and hotels!
But without university degree, it's difficult to get an employment pass.