Oh ok - i thought there was at least one other earthship near Brighton, UK - but I have never been there, so maybe not.
Yes, Earthbags appear to be a cheaper option in many settings - a hybrid sounds like a good idea :)
I was in more or less the center of Portugal, in the mountains. It was actually not a great location since the structure was built on the wrong side of the valley by someone who didn't think closely enough about what he was doing ;)
Here's some photos of the house:
https://www.ureka.org/photos/album/87337/portugal-off-grid-living

I think Portugal is a great place to go now, since it is very low cost due to 'depressed economy' - but because of that you may have some difficulties finding some supplies in some places.

Since you are used to the heat of India, you might be fine towards the South of Portugal which often receives the hot air from Africa.