There are more connecting passengers at ORD than at IAD, so it's possible UA wants to extract a premium from the ORD-LAX passenger because they'll make more flying someone BUF-ORD-LAX than BUF-IAD-LAX or ORD-LAX (or perhaps BUF-ORD-LAX-NRT is an unaccontably popular routing). At the same time, perhaps the capacity relative to demand in ORD is currently lower than at IAD, so there are fewer cheaper seats made available, and/or they have already sold out. Another factor may be that competition among the airports in the WAS area may be stronger than in CHI (or QLA), capping the fares any airline can charge, and especially since most WAS flyers will prefer DCA to IAD.

To the OP's question, yes. I am flying this weekend IAD-EWR. Three weeks ago the lowest price I could find was $168. Last week, this dropped to $119.