Hi,
I am from Ireland, Tipperary, and am a sailor as well as a prospective pelegrino (later this year), and have spent part of this summer sailing the Rias Baixas, the lovely Ria's from Finisterre to Vigo.
As well as using the Aer Lingus flights in the summer, I have also flown to Porto and Santander with Ryanair.
I travelled either by (one way drop) rental car (if arriving in Spain), or on the train, from Portugal, and found both reasonably priced and reasonably efficient, they take a few additional hours, but you save vast amounts of money compared to the (time) and cost of internal flights connections on Iberia and other Spanish airlines (like Veuling) to get you to Santiago from Madrid.
Another choice is to connect through London Stanstead, so you take 2 flights, both with Ryanair, some friends came this way to Santiago with no problems just a longish stopover, the winter schedule however might not work quite so well?
Hope this helps
If all else fails you can always walk - I'm told! There is a Camino to suit!