I did about the same trip in July 10, flew into Dublin, rented a car, drover to Limerick and played courses in West/Central Ireland. The classics are worth playing, BBunion, Lahinch, Portmarnock (Dublin) but are pricey- figure 200US for greens fees, another 100US for a caddy, and another 50 US for club rental. There are some good bargains, the local publinx are very reasonable, but club rental might be iffy. The drive from Limerick to BBunion on mapquest is truly an adventure, plenty of photo ops and small 2-pubs-and-a-church villages to navigate thru. I did the K Club (Dublin) but was disappointed with the courses. The pro shop in Lahinch is pretty cool, lots of black and white pics of the pro with some big names- Dromoland was a good bargain for golf, Doonbeg is a new course but a good taste of Irish links, and the drive from Doonbeg to Lahinch is pretty cool too.
My big trip good surprises- the local pub food is very very good, the people are very friendly. My trip big bad surprises- everything including pubs, restaurants, gas stations shut down fairly early (8 pm or so), and the cost of everything was fairly high.
There is also a sneaky toll booth on the main highway outside of Dublin on the way to Limerick, and it only takes Euro coins- make sure you have a handful-