FWIW, booked DUB-LHR-JFK thru ebookers.ie for €370. I've got nothing but time as I'm making my way back to Australia via the States slowly, so a night in Dublin is as good a start as any.
Cheers for suggestions. Still curious as to why BA wants me to be anti-environmental. Seriously, LHR-DUB-LHR, to then fly straight back over Ireland?!