I've flown a couple of open jaw itineraies in the past few years.

PDX-MCO/DCA-PDX (Q, V or W on UA - can't remember which)
PDX-JFK/ROC-PDX (L on DL)

Almost did PDX-LHR/PRG-PDX three years ago but scrubbed it when I couldn't make the ground transportation work. Fare would have been in V or W class and about the same as two RTs purchased separately (PDX-LHR and LHR-PRG).

I've also been looking at PDX-PRG/BUD-PDX for next spring and so far it's just nominal difference for the open jaw routing.