When United first started Mileage Plus, a domestic roundtrip First Class upgrade, including Hawaii, was just 10,000 miles. UA also gave a "class of service" bonus to anyone flying in First Class, even if upgraded using miles. I used to fly ORD-HNL and would upgrade with miles. However, the roundtrip would accumulate over 10,000 miles. So for every ORD-HNL upgraded roundtrip, I recouped my original miles. Furthermore, as a result, I always had at least 10,000 miles available in my account to upgrade my next trip to Hawaii.
I also did the same when flying to Europe. Just 10,000 UA miles got me a Business Class upgrade on Pan Am. As with Hawaii, the roundtrip, including all bonuses, earned me another 10,000+ UA miles. This enabled me to recoup my original 10,000 miles spent for the upgrade. Those were the days!!
[This message has been edited by Neal (edited Feb 12, 2004).]