What an odd example, those cultures people expect haggling and they will dramatically increase the starting price if you're a Westerner. You could be asked to pay 10x what they'd be willing to sell it for. You absolutely should haggle if for no other reason than to experience their culture a bit deeper.
It's far from being rude or inconsiderate—especially not "unethical".
It's far from being rude or inconsiderate—especially not "unethical".