Hi again. I had not thought about the round trip option. But now that I am looking at that idea, it seems like the flight I would need (leaving at 9:35am) is too expensive (over $400) so unfortunately it won't work this time, but I appreciate the idea and I am certain I will keep it in mind for other trips.
I guess I will be doing the bus!

Bill, I just booked a r/t ticket on Iberia. I have been checking on the prices for days and finally something came up. I have to get to La Coruña airport, but I still think it is going to be better than taking the overnight bus. Again, Thank you for the suggestion. I had never thought about that option before.

Last week I booked on the Iberia Express,a new division of Iberia.Roundtrip Madrid-Santiago 65 euros in September! They are only offering flights right now to just a few locations.