Viajero, I assume that what you're saying is that it is simply a OW-imposed constraint (not IATA or any similar legal constraint)? That is, we will charge you (because we make the rules and therefore we can) the higher of the price where you originate or the price where the person-who-presses-the-ticketing-button is sitting? In an era of electronic ticketing, that makes no sense (other than giving the airlines greater revenue and/or causing additional effort on the part of the customer). If they're willing to sell a DONE4 ex-NRT cheaper than a DONE4 ex-US, that's great - but why make me go through the hassle of calling AA in Tokyo when AA-US has done all the work to set up the ticket for me and could (presumably) push the button just as easily as the people in AA's office in Tokyo?