We've had this discussion many times before in the past. The audience you can reach increases over time when your price goes down. With two competing products, if they are generally considered of equal value, then the one that has the lower price will reach a larger audience sooner as well as have a competitive advantage.
But of course companies like Apple show that given the right featureset, customers are willing to buy products at a premium price, so it's not a law set in stone. The Xbox got its strong position in the U.S. not just because of the success of the 360, but also because they started being successful already with the original Xbox in the U.S. (that one also sold 2x as well in the US as it did in Europe). They won't lose this advantage overnight.
But of course companies like Apple show that given the right featureset, customers are willing to buy products at a premium price, so it's not a law set in stone. The Xbox got its strong position in the U.S. not just because of the success of the 360, but also because they started being successful already with the original Xbox in the U.S. (that one also sold 2x as well in the US as it did in Europe). They won't lose this advantage overnight.