Assuming you're living in SF Bay Area with ~120k/year ($10k/month) income:
Your earning after tax is ~$6600 per month. After ~$1800 rent and ~$1700 living costs (transportation, food, utils, ...), you get ~3100 in capital savings.
In Singapore, your personal income tax is nearly zero. To match that savings target and quality of life, you only need to earn SGD 7000 per month (~US $5200/month, or $62k/year) and you gonna spend about $1100 for rent and $900 for everything else (without car).
P/S: I'm a non-US citizen, lived in Philly for 7 years, got 120k offer in SF but declined, now working in Singapore.
I had 6 months experience (in tech, anyway) when I arrived and still made 7.5k. In fact, that offer was made 4 months earlier, so with 2 months "experience". I was saving about 50-60% of that.
I think what salary you get can span anything from 2k to the sky (realistically, 20k and above will be very hard, and probably in finance or management). It's all about - here more than anywhere in the world - demonstrating value to the person signing the paycheck. If your value is much higher than what you want, then you can pretty much name your price. The tough part being convincing someone that you are worth that much. I think the rate for an American in a good corporate data science team should be at least 10-15k.
The marginal cost of foreigner vs local is, at least at these salaries, the flight. The EP costs $250/application and takes about 7 working days, with no quota. You turn up at the EP centre, pick up the card, scan your finger and you're gone within 5 minutes. Flying coach, you can get a return flight to the US for around 1k, less if you wait for a good sale. So, trivial. And it's easy to change employers - if you get a new offer, just get THEM to apply for EP and as soon as you have it, quit the first job.
Just be aware that flying to the US just plain sucks. London is a direct 12-16 hour (depending on direction). The US is one stopover, probably 20-24 hours. East coast worse than west, obviously. The other thing is expatriation has some invisible but very real downsides, the most painful one being away from family basically forever. On the upside, they get to visit an exotic country.
Your earning after tax is ~$6600 per month. After ~$1800 rent and ~$1700 living costs (transportation, food, utils, ...), you get ~3100 in capital savings.
In Singapore, your personal income tax is nearly zero. To match that savings target and quality of life, you only need to earn SGD 7000 per month (~US $5200/month, or $62k/year) and you gonna spend about $1100 for rent and $900 for everything else (without car).
P/S: I'm a non-US citizen, lived in Philly for 7 years, got 120k offer in SF but declined, now working in Singapore.