Great thread,
I have my own personal experiences. With my project I am lucky to have a gringo who has lived in R.D.20+ years who knows the culture and speaks spanish and married to a Dominican.
We use a Dominican for the concrete work. Junior hires the guys and we only talk business with Junior. One day, when the pump house was near completion two workers started complaining about money. I kept quiet, Thomas told them not to mix and concrete. We called Junior and told him he needs to tell his guy, who ever isn't happy pick up Thier tools and leave. We have 10 guys who want to work. Junior said just that and that was the end of . The job was done quickly, correctly and looked fantastic. We set a chain of command and stuck to it. I the owner do not deal with the help, out side of general conversation. I alway show the same respect I show to everyone. Thomas deals with the guy we hired and junior deals with his crew. This way the crew saves face, and junior is the bad guy, not the rich gringo. Plus we say what we do, and do what we say. No flip flopping.
I don't expect local to understand money in general. They don't have the opportunity to make lots of it, how to manage what they have , forget about them understand how money can make money. Maybe in a couple of generations the average person will. Not in today's world.
Also I agree with the other posters, if you know the price ,pay it. Don't ask, that's a sign of weakness pay it and walk out. Be fair but firm, be firm but not aggressive , if your aggressive leave an out so that person can save face. Remember more guys, that's all they have, if you dont, be prepared for payback when you least expect it.