Dublin is best when the rain taps the glass and a fiddle player kicks off in the corner of a warm pub. The history sits right on the street, from the walls of Kilmainham Gaol to the grounds around Trinity College. The sweet spot to visit is between January and March, when summer crowds clear out, airfare drops, and the pubs feel like they belong to the locals again.
A typical week from the US runs about $2,100 once you cover flights, a central place to sleep, and your pints. If you want to keep your savings intact, you can charge the trip upfront and clear the balance in steady, predictable monthly installments without paying extra in interest.
Keep in mind that the promotional window is a hard deadline, not free money. If you still carry a balance when the 18 months end, regular interest applies to whatever amount is left. Set your automatic payments from day one so the balance hits zero before the rate jumps.