We foreigners are not here to change the world and help every Dominican we meet. Dominicans hate when we come here and overpay for services like cleaning, gardening, building, etc. If we pay more than the 'going rate', that person then thinks they should always be paid that, and when we move/leave/hire someone else/etc that worker expects to be paid the same for less work than before.
On the other side of the equation, what a hard-working Dominican can charge is lessened by the use of illegal Haitian labor. The "going rate" is based on exploitation of the Haitian's status and previous experience with poverty. And, yes, I understand that an exploited person can be thankful for having been exploited.