I'm trying to plan out a two city trip to see some family in March. Getting from DC to Chicago is very cheap (<$100), and getting from Chicago to Indy is also very cheap (<$100), but getting a ticket home from Indy to DC nonstop is like $400.

I tried a few different days around March to see if maybe I had just hit a major event, but no, pretty much any day in mid-march is $400.

The weird thing is, if I want to go out of my way and connect, it's only $100.

Why is non-stop service from Indy to DC so expensive? I ask only because I can see myself making several trips out there in the next few years. It would be nice to fly direct for a decent price. Are these prices reletively normal? Why would they be so different than DC->Chicago prices? I know prices fluctuate but the large gap between Chicago and Indy has me puzzled.