I don’t know how long is the long run for you, but Delta is right now offering RT to Vegas for $444 non-refundable and $638 refundable. I didn’t go check all the other carriers, but I definitely recall tickets with more flexibility (sometimes including refundable, other times creditable) being sold at higher prices than less flexible tickets.
As a buyer that makes sense to me; it costs money to provide flexibility; it’s worth it to some buyers but not all, so buyers can opt into the level of flexibility that matches their preferences.
