I am travelling to Dublin on a weekend in Sept. We will be driving from Galway. Friends suggest that traffic in Dublin is crazy and hotels/BnB too expensive; especially if you are also trying to park the car for the night. They suggest staying outside Dublin at any of several close suburb towns with access to commuter rail. Any suggestions?
Google a DART map for easy to access to transportation into the city from outlying towns.
Rick recommends looking at Howth (northeast of Dublin and not too far from the airport) and Dun Laoghaire (southeast of Dublin), both on the DART train lines. His Ireland book lists accommodation recommendations in both places. I don't know if these would be easy from Galway, or if there are better alternatives.
You might consider this B&B, worked for us -- with similar concerns -- in May 2018. https://www.annaghhouseclontarf.com/
Local bus stop across the street, 15 minute ride into central Dublin; never waited more than 5 or so minutes for a bus. Free parking. Nothing fancy, but we didn't do much more than sleep there (in a nice room overlooking the Bay.) Good breakfast, "full Irish." Also found an excellent seafood restaurant a short walk from the Inn.