That's a difficult question to answer without more information. The best is if you make a list of all journeys you'll be making and then compare:

1. Check prices of normal tickets on the RENFE website.
2. Check if a Eurail pass for Spain would be cheaper to cover all or part of these journeys. Do take into account that you'll need to make mandatory reservations for almost all trains on top of the pass, see this list (scroll down to Spain).

On top of the mentioned page of Renfe by @rvdborgt 

Check the website of AvloRenfe (The cheap no frills subdivision of Renfe)

AVLO for now ONLY serves Mad-Barca and soon to come Mad-Valencia.

INside Andalucia (the first 3 towns) there is also a good BUS network mostly by ALSA-often a little cheaper as trains, and f.e. for direct Cordoba-Granada even quicker, as more direct. And mostly much, much easier to book-just before setting off or when arriving in that city for next leg. I know-I have used this 2 weeks ago when I travelled there.

With a EUrail 1 country pass you still have to visit the counters, show pass, and make the REServations and pay for them. canNOT do online, so my guess is that online booking will be a little cheaper and more comfort for the mind.