I believe the price quoted states that the segment may be as low as $XXX. To actually get a low RT far based on a series of very low segment fares, a number of byzantine UA requirements would have to be met. UA has engaged in this kind of low-ball price-quoting for as long as I can remember.
However, note that for higher-priced (less restricted) segments, the RT fare will often price out as the sum of the legs.
[This message has been edited by UAL Traveler (edited 11-28-2000).]