My local Sainsbury has its film on offer. From memory, Superia 400 24exp was down to £2.50 and 36exp was maybe £2.75. Best of all, Gold 400 3 packs were just over £4. Some mail order places may better those prices but if you're there anyway buying your sausages you pick up a roll or two.
Thanks for the heads-up! The Superia isn't particularly cheap, but the Gold 400 sure is. Are they short dated?