Actually I was just playing with it. Generally when I go to the States I'm told to arrive at the end of the week before I start work on the Monday to "get on their time zone". I can go anywhere I like for that weekend, so long as it's not horrendously more expensive than an alternative. They don't like NYC, for example, due to hotel costs, but LAS is fine.

So I was seeing where I could go on this trip and LAS is my usual default. I got it to price, and then for fun threw a BOS on the end of it to see what happened. To my amazement, it priced without going up by ŁKs.

Basically I did a standard DUB-LHR-JFK-LAX-LAS (I don't do PHX anymore - no-one needs TPs that badly) and then just tagged a BOS on so I didn't stop in LAS.