OW doesn't have anywhere near the consolidator fares of Star. So your perception is correct, if low fare matters you won't be flying Oneworld. Partly its brand strategy, partly its load factors. CX does have some consolidator fares that are good, but only on certain routes, and generally have to buy through a Chinese travel agent. Not sure that MIA has much of a chinatown; you might have to buy through SF/LA/YYZ. The Oneworld strategy is not to lower fares but to increase service, for example BA's extensive "buy J, fly F" offering and sporadic "free companion fare in J/F". I doubt that this will change and will probably remain a Star/Oneworld distinguishing feature (cheaper to fly Star, better to fly Oneworld ... though the latter is a rather fragile attribute, and LH seems to be making a run at the BA F business).