Originally Posted by
Globaliser
The point is that this hasn't just been thought up by BA in an effort to find something to maliciously direct at you, which seemed to be the tenor of your post. You may only have come across this for the first time now, but it is a long-standing feature and there is standard advice here to minimise its effects (usually to buy two one-ways, whilst remaining alive to the risks of doing that).
I also understand that BA is hardly unique in offering differing prices on international flights depending on the country of origin. I suspect this might have also been true of domestic US airlines for flights solely within the US before the introduction of one-way pricing at half the cost of a roundtrip--in other words, ORF-NYC RT may have been priced differently than NYC-ORF RT.