Najsh (Hadith No. 1845)
Volume 3, Book 34, Number 350 :
Narrated by Abu Huraira (radiallaahu `anhu)
Allah’s Apostle (sallallaahu `alayhi wasallam) forbade the selling of things by a town dweller on behalf of a desert dweller; and similarly Najsh was forbidden. And one should not urge somebody to return the goods to the seller so as to sell him his own goods; nor should one demand the hand of a girl who has already been engaged to someone else; and a woman should not try to cause some other woman to be divorced in order to take her place.
Since market rates, trade practices and customs can vary in towns and deserts, it’s better for natives to run the businesses in their lands.
Najsh – means to offer a high price for something without having the intention to buy it but just to cheat someone else who really wants to buy it. This is forbidden in Islam because it’s deceiving. The potential buyer will be deprived of the thing he wants to buy and the seller won’t be able to seal the deal with either of them.
Causing harm in general is a character trait not befitting a Muslim. Please refrain.