Well that's really an oddball set in these parts but it looks like a good quality set. Id pay $50 in a heartbeat just to own a decent set (even though the chances of using British thread are near zero).
I think shipping would put the price out for me. Even though IF a person NEEDED a set of BSFT left that would probably still be a reasonable deal. Maybe somebody that REALLY needs a set will find them. I would only possibly use them once in a blue moon in gun or steam engine projects that I haven't even started yet.
Just need 25 boxes of left hand fine British fasteners to go with it! Then everything you make will be perplexing to everyone! Kind of a machinist joke...