Originally Posted by
blueflower22
We are based out of SFO so our plan is to fly to London and take a cheap flight from London to Barcelona.
You are aware of London and UK "carbon tax" on flights departing UK?
While not as high as Biz, those taxes do add up.
Haven't looked for reward flights, but most of my paid trips to Europe in last 5 years have been to MAD, even though I only spent a day there (and it is a nice place to visit).
MAD has consistently been cheapest place to fly to from US IME for last few years. Again, points may well be different. But UK taxes on flights FROM are rather high.