Santiago to Rome

Looking at how I am going to get to Rome from Santiago in mid-May. Not entirely sure when I am going to finish the camino, but I'm starting on April 17th from SJPdP and figuring I'll get to Santiago around May 20th, possibly go to Finisterra, then need to get to Rome.

Couple of questions:
1) Should I book ahead of time?
2) Should I fly?
3) Should I do a combo of trains/planes and bus to get there?

I'm in no hurry to get there, and at the moment don't have any real plans for that part of my trip. I know I have from the end of my camino until June 20th to hang out in Italy (or Croatia or anywhere near there) and possibly do a work exchange for a bit. Also hoping to visit my cousins in Abruzzo for a bit. The only real plan is I hope to spend June 10th-20th in Rome exploring more of the religious sights I didn't see last time I was there. Everything else is still being worked out. I just need to make sure I am in Rome by June 20th to catch my flight to Tel Aviv.

So, any ideas on the best way to get to Rome from Santiago? I will be on a tight budget, so cheap is good.

I will look into Ryanair. The only problem with that is if I decide to go to Finisterre, I might not get back in time for my flight....I've also heard they have all kinds of hidden fees too. I'm not sure if it's worth the trouble..... Thanks everyone!

Ryanair has a one-way to Rome for 105 Euros. I'm wondering if I should buy that or should I maybe take a bus to a bigger city that might have better fares. I know it's a good deal, I just want to check around a bit.