This post that was quoted has been deleted.
In addition to the living costs quoted, please budget for around 12%-13% on top of the purchase price of a property for purchase tax (8% in Murcia, compared to 1.5% for Stamp Duty in the UK), legal fees, etc.
As mentioned, you need to take out private medical insurance for the first year - we're looking at this and have been quoted around €65 pp per month (without pre-existing conditions). You can then choose to continue to pay privately, or pay into the Spanish healthcare system - which is generally thought of as excellent - for around €60 per month. Then when you reach state retirement age, this is free (although this may change after the Brexit Withdrawl agreement). I don't know how this works if you were classed an as Irish citizen.
If you decide to get a car, fuel is slightly cheaper than the UK, as is road tax. However, used cars are more expensive and there is a lot less choice than the UK.
Hope this helps!