United and Air Canada have fares between Boston and Ireland — either Dublin or Shannon — from $385 roundtrip.

Fares are available for outbound travel September 1 through October 31, and again April 1 through June 15. A Saturday night stay is required, and there’s a $300 change fee.

Ha’penny bridge on Liffey River, Copyright Copyright tupungato / 123RF Stock Photo

Most sites are showing $461 as the lowest fare, which is great.

However airfare metasearch site Momondo will help you find even better pricing than that.

The cheapest available tickets are United K fares, $85 plus tax each direction.

You’re not going to upgrade these tickets. If you’re a United elite, choose to fly United and not an Air Canada flight with a United code on it for access to economy plus extra legroom seating. And if you’re interested in earning the most miles you’ll choose to fly United — meaning connecting in Newark or Washington Dulles rather than Toronto — because you can credit the miles to Singapore Airlines KrisFlyer and earn more than you would any other way.

While a non-elite MileagePlus member crediting United flights to the revenue-based MileagePlus program will only earn under 900 miles (5 miles per dollar on the cost of the ticket excluding taxes), nearly all United fares earn 100% of flown miles when crediting to Singapore Airlines KrisFlyer (.pdf). That means you earn around 6000 Singapore Airlines KrisFlyer miles for the trip flying United and crediting this K fare to KrisFlyer.

While Singapore miles do expire after 3 years (not 3 years of inactivity), you can top off a KrisFlyer miles account with transfers from American Express, Chase, Citi, and Starwood.

(HT: Secret Flying)