I think you want to get out of the factual thing again but I can tell you: The pay hasn't changed, unless you are signing the agency's contract.
Pay was pretty similar when I started, it went down around 10% and is now the same again. On top of the condition you mentioned, there is also a pension scheme for permanent residents (which you are free to apply after a year or so?).
What has increased are the cost of living since then. During my three years I've been there, housing has basically doubled. You get 3000$ housing with one of the agency, which should cover a reasonable apartment.
You also have to consider that cost of living is varying widely, depending on your way of living. If you go out and drink alcohol regularly, SIN is a quite expensive place. On the other hand, if you like local food, you get away very cheaply. I was able to safe a considerable amount of my salary. Most of it I left there, since the S$ will most probably appreciate against western currencies. It's pegged against several Asian currencies and US. If the Yuan is going up, the Singi will, too.
Open for other well considered questions...
Dani