Hi - I am sure a more informed answer may come but believe this has something to do with how the website prices these tickets, very much in BA's favour and I have been caught out by it pre joining Flyertalk. I think you should expect it to be the standard PE price plus a small uplift in taxes and the relevant avios. You will likely need to call to book, probably not a bad thing as not sure I consider the BA website safe/secure until further notice. They should waive the phone fee if the booking impossible via the website.
EDIT: also remember seeing something recently about change in carrier YQ for J/F.. perhaps this is the reason and in which case not worth it at all.
Last edited by lavajava; Oct 27, 2018 at 1:15 pm