I called UA about changing the return portion to a reservation once travel started and they said it would be possible and entirely without restrictions as long as you pay the $200 change fee and pay the fare difference.

I asked if you could change the city on the return and they said no problem and that it would be the same thing (change free + change in fare).

I made sure it wouldn't be the OW price, but based on the return portion of the round-trip flight.

I'm a little skeptical about taking a phone reservation agent's word as golden, but she seemed rather sure about it. Does this sound right to you guys?

P.S. - They said it wouldn't be possible to keep the outbound if I wanted to change the return without it being repriced.