I'm married to a Spanish senorita and live in Spain. there are quite a few wedding planners here who shall do as much or as little as you need regarding the weeding. I guess you should save about 25% or more on the cost of an Irish wedding.
You have to figure in the expense of travel but at least you have a 90% chance of sunshine and lack of rain, unless you are very, very, very unlucky.
Check out
www.spanishweddings.ie
www.javera-organisers.com
www.theweddingguide.eu
www.destiniweddings.com
all of whom can give you a little insite into getting married here. Note that barcelona and malaga weddings will turn out to be the same price if not more, than an Irish celebration.
If you are having a wedding rather than a blessing, you really will need the help of a planner to help you with all of the poapperwork required, no matter which foreign country you decide to have your celebration in.