We study how smugglers may respond to different types of migration policies -legalisation, through the sale of migration visas, or more traditional repressive policies through borders' enforcement or employers' sanctions- by changing the price they propose to illegal migrants, which affects the number and type of migrants. In this context a government that aims at dismantling smugglers and controlling migration flows faces a trade-off. Dismantling smugglers by the sale of migration visas necessarily increases the total number of migrants and lowers their average skill level. In contrast, repressive policies decrease the number of illegal migrants and increase their average skill level but reinforce the smugglers' abusive power as they apply higher prices. We show, however, that a package of both types of measures may be effective at dismantling smugglers' businesses and controlling migration flows, without necessarily increasing the budget deficit. We then calibrate the model to quantify some of its policy implications.