Looking for a simple direct WT flight back into LHR two weeks out - on BA.com it’s £850, while on worldairfares.com through Skyscanner it’s £580.

1. how does worldairfares manage to charge so much less and
2. is it safe to buy the ticket through them?

I understand that making changes etc will be a nightmare, but it’s two weeks out so no schedule change, it’s non-refundable or flexible in any case, and if it all goes wrong (last minute canx, etc) then I don’t think I’ll be significantly worse off.

any experience/thoughts?
thanks