I love to travel and have and continue to do so on a frugal budget. While gas and taxes could change and other events effect things, $3K sounds like a lot unless you are flying out of a small town. (I live on the west coast and fly out of LA) In that case it may be worth looking at alternatives to getting to a hub airport. I have seen in the past that the BA site, as an example, has listed really small airports in the US that I am sure they use alliance partners and may not be the best bargain.
I know different seasons and different rates and all that but I am flying next month LAX-LHR and used a consolidator and have not found a carrier that has beat or matched the fare yet.

I admit to being extremely prejudiced by if you travel through the north east enroute to Edinburgh a stop in Northumberland is nice, and if you get a layover on trains and are in Newcastle there are many a fine pub to be found. (I recommend the Crown Posada by the Quayside)