A RT ticket on American was $1,200. A RT to Jacksonville, with a stop in ATL was $400. It would have been great if we could have booked to Jacksonville and just got off at ATL. We looked a lot of options, even the cost of a RT ticket from Jacksonville to ATL as an add-on to the $400 ticket, but we couldn't work things out.

We ended up booking a RT flight on another carrier with a stop in Houston for $600 or $700.

Airline ticket prices often make no sense at all.