The easiest way around this is:
1. book with a TA who has a good relationship with the airline (and thus should always see the best fares)
2. clear your cache/cookies and hit ua.com without logging in, search out your trip, book it, then log in when prompted to enter your traveler details so UA's systems won't notice who is booking during the pricing portion of the process

I can't imagine the US government would permit an airline to charge a customer a higher fare over and above the lowest published fare on file just on the basis of that customer's relationship with the airline - essentially forcing a specific class of customers to pay higher than published in order to fly.