Round Trip or 1-Way?
 

A Round Trip ticket is much less expensive than a one-way ticket for a flight from FCO to BCN. What are the possible difficulties I might have by purchasing a RT and then using only the outbound portion and not the return? Thank you

none

We did just that - $133 round trip - over $300 one way. That is so stupid to have one way more expensive than round trip.

None unless you do it on a regular basis or you have status with that airline

Thank you to all responders. We will go ahead with the RT purchase.

The risk is that the airline has the right to come after you for the one way fare. The probability that they would do that is very low to maybe zero.

fmpden - I was wondering about that - if they could charge us for the one way. What happens if you decide to stay a few days longer? Hmm! Wonder if anyone has had experience with this.

I am not sure if I understand your question. If you stay a few days long you break the ticket and pay the change fee IF you don't have a ticket class that allows for free exchanges. Or you buy an open end ticket. Lots of options.