no profit, bad workmanship work, chin chai will do ....
have profit, good workmanship work
I always give NETT quote, I do not quote high then let customer to discount,
so IF customer is steady and let me do my work,
of course I will do nicely for them ...
and I also will use better material for them ...
minor addition also no extra charges.
But if customer is tooooo kira-kira,
then we also kira-kira with them la ....
many people don't want to let other people earn them one ...
they feel unhappy ....
for forumer, can check out my FB link below and check out those "BAD WORKMANSHIP" .....

i deal with projects (mostly non construction related). From experience customer want to pay one, and get more than one things to be done, but not willing to pay extra or act don't know. My job is to make sure what they request are in line of what they pay, sometime we do give free here and there to make them happy but not overdoing it. If they need something and don't want to pay who going to pay my resources? who going to pay my company operation cost?
Always remember, There Are No Free Lunch In This World!, only parent will give free lunch.