I use google.com/flights. Put in MCI for the origin, leave the destination blank. Put in a date likely to be cheap (11/15 or 12/6 are good ones right now), same date for outgoing and return. Choose the alliance under the airline dropdown box. Look carefully at the map to find cheap cities, zoom in enough so that you can see the smaller places.

When you find a candidate, click on the city on the map. Then click on "show flights" and see what is on offer. You can click on the "bars" symbol just below the return date to see a fare calendar. Poke around until you find something you are content with.

It is usually possible to find segments under $50. From some cities you may do better.