We went in April, the week before Easter. I had every hotel or B&B planned and reserved in advance. I'm as obsessive about all my trips as I am about Disney and the idea of having to find a place to stay that day makes me ill 
I honestly don't know how much the whole thing cost
I know the plane tickets were probably around $700. All of our places to stay ranged in price from 99 to 140 euro (Except where we stayed in Kenmare, we sort of splurged and stayed at an uber-fancy hotel). The rental car was under 200 euro for the week (most cars are manual drive, so DH drove everywhere. In retrospect, it might have been worth the extra cost for an automatic so that I could drive and he could enjoy the scenery). We tended to eat very reasonable meals in pubs or restaurants recommended by the hotel.
The green Michalin book, as well as the Rick Steves book are both must haves for a self guided tour. They were both fantastic for getting around. I'm more than happy to answer questions, we had a great time!

I honestly don't know how much the whole thing cost

The green Michalin book, as well as the Rick Steves book are both must haves for a self guided tour. They were both fantastic for getting around. I'm more than happy to answer questions, we had a great time!