It doesn't work out from the perspective that you are looking
at. Some projects are mediocre but some are high end, there's no
fixed amount and i wouldn't use "average" as a word in this
field.
Apart from that, i'd be going too much into personal details
which i don't see a need to share over the net. Happy figuring out
from your sources over the internet. All i can say is, you're no
where near from what you have assumed.
By the way, just an advice, if you're in Singapore, focus
on yourself first before trying to figure out and calculate someone
else's payslip.
If you want to smoke, go find a better place to do it. Not
here.