Society and media should well supervise employers on their promised payment to migrant workers.
Let' leave the decisions to the migrant workers themselves:take the job or not, salary is enough or not, workload is acceptable or not and etc.., since only they themselves know what standard they want to gain: feed a family, educate children or they want to own real estate in cities. This is fair to every one, migrant ppl or locals.
The weakness of the migrant is protecting themselves from losing what they are promised to have, which need society to keep an eye on the greedy employers and give a hand to those who can not abtain what they deserve.