I’m looking at some BA flights: outbound from LHR to SAN (15 May) and return from LAX to LHR (1 June).

If I book via BA.com, the total is £732.32, but via AA.com it comes to £717.52. The outbound is WT (“economy standard”) and the return is WTP.

Is there any reason I shouldn’t just book via AA.com and save £14.80 instead of booking through BA?

I did consider booking through BA.com and then making a claim under their “Best Price Guarantee,” but I’m not sure whether this situation would be covered.

Thanks in advance for any advice!