Someone gave me a gift card as a present, am i allowed to sell it? someone mentioned that it may be עני המהפך בחררא since the person buying maybe would anyway buy from that store?
It is permitted,as long as you are not buying it from inside the store itself. When someone is outside of the store they can always go to a different store to buy things, therefore it is’t considered taking the sale or money away from them. However when the customer is already inside the store then, by selling them something, that would be taking away business from the store and would not be permitted.