Originally Posted by
findark
Yes, UA site has a known "feature" where you can search A-B roundtrip and it will find you an A-B-C-A routing which is fared A/C with a stopover in B. It will then show a "segment price" A-B equal to half the A/C fare, and a return B-C-A trip with a "segment price" of 150% of the fare.
Thanks for the explanation! Very curious "feature."