The 3 universities pay quite competitively -- although as pointed out, ceteris paribus, SMU "usually" pays better since it is newer.

I received my PhD from one of the US universities that the OP mentioned in the 1st page. Received an offer from one of the universities in Singapore (Asst. Prof position). I don't remember the exact figures, but the pay is $12k+ per month, with additional research money.

Some comments for those thinking of doing PhD
1. Getting into a top program is essential if you want to land a good job thereafter. The prestige, training, network, etc all come into play.

2. But getting into a top program is highly random. Top PhD programs are highly selective, and they only accept few students per year from all over the work.

3. I'm not sure how important your undergrad grades is in helping you to get into a program. I "only" have a 2nd class Upper from a local university, and I got into one of the top 3 programs in my field. Go figure (But I do have a 99-percentile test score and some crazy work experience when I was applying.... those might have helped...)

4. Suppose you do graduate with your PhD. Congrats! Now, there is new uncertainties in term of your placement. You would be competing with a pool of highly qualified PhDs (newly minted + senior assistant profs who didn't get tenured) on the job market. The prestige, training, network from your school can help you to open some doors and maybe get some flyouts. But after that, very much depends on how you perform during your job talks and interviews, relative to other job candidates (i.e., your competitors). It also depends on how good the job market is during the year that you graduate - and there is no way you can predict what's the market is going to be like in 6 to 7 years time.

Finally, a job in a good/top university is going to pay you well. After being a poor and broke graduate student for 5 to 6 years, any amount would seem like the best gift from heaven . However, while the starting pay is attractive, the _increment_ from year to year isn't going to be huge, compared to what happens in the industry. If $$$ is what you are after, go do an MBA.