PG, are you registered in the advanced mode? If not, go to your user profile to fix this. In advance mode, you will see the fare class inventory. If there are zeroes next to the V and other low-fare classes, then you're probably being quoted one of the higher fares.

Going to Europe from the USA, the taxes should only total about $60-$90, depending on the destination. LHR tends to have the highest taxes if I recall.

Also, in booking my mileage run this weekend to MUC, I noticed that UAL.com did not consistently offer up the lowest fare. Sometimes, it is good to cross check with Expedia or another travel site or call UA directly (I realize you lose the online booking bonus).

If you're trying to book for this weekend, I think the only under-$500 fares left to Europe on UA are to Germany. MXP was pricing out about $50-$75 higher than MUC/FRA and BRU/LHR/CDG were through the roof.