Laser radial sail price

yes, the business model is to buy them from a rather large sail factory in the fareast.....where the labour part of the model is not earning UK minimum wage.
if you actually asked a uk sailmaker and i mean  a sailmaker who actually physically makes sails and not one who orders a sail to be made for them in another country, to make a radial sail that they design, cut and stitch together do you think it would still be significantly cheaper than £549??
likewise a crosscut dacron sail the materials cost the same pretty much wherever you are in the world so a £200 sail is saving on labour costs mostly (some of the replicas i have seen use a cheaper cloth).
the unfortunate fact regarding the laser sail is that it is made in warehouses with cheap labour. Buying a replica is supporting no one really but large industrial sailmakers and forcing smaller sailmakers to cut their profits to compete against huge multinational sailmakers.

North Blaze sails went from £760 to £895 overnight recently, thats 18%, almost exactly corresponds to changes in the Dollar/Pound exchange rate at the time.

Exactly. I bought an old Laser for less than the cost of a Laser sail, to have a fallback if I can't find a crew for my Ent. I haven't got any prospect of getting "into the chocolates" at our club races with it, and frankly, I don't care about that. 

But, given the longevity of a 'real' Laser sail, a £200 replica is probably no less good a product and there is no reason why Laser couldn't build their 'official' sails for a better price.

But a Laser 'training' sail can be had for £200...... They have a business model too and aren't making them at a loss......