I always purchased these from Home bargains as they are the cheapest (£1.49 for 600gm). But this time Farmfoods beats them. Also the expiry is January 2019. You can stock up if you use a lot and use Farmfoods vouchers to get this price down further.
Also if your in Farmfoods, have a look at the Young's Chip Shop Fish, large size, 2 in a box or 6 Brains Faggots for a pound.
I paid £4 for 2 boxes in Asda - so that's a bargain!