Buying new OW instead of changing RT return leg
I have a RT on UA and need to make a change to the return leg. However, UA is trying to charge me some exorbitant amount for this change. I noticed that I can buy a OW ticket on the desired return flight (on UA) for much less than the change cost on my original ticket.
Should I do this? I presume my first itinerary would cancel itself for no-show (on the return leg) and I would then simply fly back on the second OW ticket. However, I also read somewhere that airlines may decide to charge you for not using the return leg, although this is very rare.
Has anyone had any experience doing this?