Code for 50% discount on selected items : http://merchandise.thedoctorwhosite.co.uk/bbc-shop-site-exclusive-50-off-selected-items/ It works - I've just purchased Season 8, the 10 Christmas Episodes box and the Compete Specials box - all on Bluray for just under £41. Postage free too.
Further to this, I've discovered that the BBC Shop is actually closing at the end of March and there's lots of stuff being sold off from cookbooks to Blurays, not just Doctor Who merchandise (of which there's more on sale now).