Might be worth checking out the ex EU fares on BA from Dublin in Business, I've managed to find £1250 return DUB-LHR-LAS for June. Thats cheaper than PE from London. To get that price I found the cheapest dates and then searched expedia (try Irish and American sites) for a cheaper price, and plenty off a hotel as well if you need one. LHR-LAS and hotel would of been £6k if booked separately, or £2300 on Expedia from DUB