When I searched domestic award tickets, the display on the amount of taxes was within a factor of 2 ($11.20 instead of $5.60), which would eventually be corrected at the end of the booking. However, the displayed amount was much higher today (12.5k miles
+$80.60). I guess that the programmers did work too hard last night.

Edit: Never mind, $75 close-in fee was added to the total even though the fee should be waived for me. United did not charge it when the ticket was issued (It was displayed throughout the purchase process). But I need to double check my credit card.

Edit2: The credit cards were charged with $75 close-in fees. The receipt says: "Award Booking Fee $75." On the "manage reservation," it was twice as much ($300 for two tickets).