is there really much competition? chile is in the southern hemisphere, so the seasons don't match up. i would have thought that when american peaches are in season, chilean peaches will be terrible, and vice versa.

as for transportation - america is a big country. i am not sure "local" californian peaches on the east coast will suffer much less than chilean peaches - in both cases, significant transport is necessary.

disclaimer: i live in chile.