As Guy Betsy mentioned, I've actually had the UA rate desk say NEIN!!! to my attempts to get the rate applicable to the country of origin when I was purchasing in the US from a US based agency.

I'm away from my office, so I don't have the rules available, but I seem to recall language saying something like "if the fare from the country of purchase should be higher than the country of origin, or vice versa, the higher of the two fares shall apply."

Others may know better than I, but I don't think the rules always read like this, but when they figured out what people were doing, they tried to make it as difficult as possible.

Greg