I'm looking for flights to RHO and on skyscanner I saw an option for LHR-DUS-RHO/RHO-LGW where the second flight is on AB and the rest on BA (taking the connection on the outbound is significantly cheaper than the direct BA flight). I cannot bring this fare up on the BA or AB sites; but it is bookable on Expedia for example.

I'm trying to figure out the baggage policy for this. Expedia says the outbound is a Q fare and it includes one checked bag and the return is a N fare and a checked bag would cost £56. But following the link in this guide:
http://www.britishairways.com/en-gb/...weight-baggage
I see that for an HBO fare the baggage fee for RHO should be £35. Also if Expedia is wrong and there's no baggage allowance on the outbound, then the outbound fee would be £65 if I'm reading the table right.

Do you have any suggestions as to how to figure out the baggage fees for this trip without being stuck with a non-refundable reservation?