Amazing the way these calculations work out. We're going to England next spring, using American Airlines points. The flight selection offered us flights on British Airways and American. The AA flights cost the points plus government fees. The BA flights cost the points plus the government fees, plus enough surcharges to make a $1000+ difference.
If I only had the BA flights, I'd certainly rather find a low-cost carrier! It will be interesting to see what happens in the coming year as Aer Lingus joins BA's parent company. Can a generally discount carrier stay that way in that company?