I believe that Dublin is a rather small city and therefore does not need this post. If you want you can reach every corner of the city on foot, but in case you need a post on the costs of the tourist tickets, here it is :)
In Dublin there are Tourist Tickets created for travelers who intend to stay in the city for 3 days or more. Tourist tickets are in fact valid for 72 hours and has no travel limits for these 3 days. For 3 days for the price of 26€ you will have included the transport in the center city (all Dublin Bus), the Dublin Bus Tour - hop on hop off e Airlink to the airport. Children under the age of 14 can have the same services but at the price of only 10 €
Other benefits, not in packages, are instead i daily tickets. All include unlimited transportation for the day or days in question, and transportation to and from the airport.
1 Day Adult costs 6.20 €
3 Day Adult of € 13.50
5 Day Adult of € 22
10 races for 90 minutes of travel for € 19
30 Day Adult at 110 € (valid only for 30 non-consecutive days)
1 Month of unlimited travel 110 €