Who cares what the average salary is in Singapore?
You're in the US, earning US dollars.
Unless you really want to come to Singapore, or are being laid off over there, I don't see why you'd want to peg your future salary to the much lower average of another country, and take a pay cut, to boot (though not a very big one, it seems).
But to answer your question, yes, $150k + housing is good by local standards, especially if you pay local tax.
You'd probably have more cash in pocket over here.