Just been into Sainsbury's at Worksop because in urgent need of cereals for the morning and found these at what is I think a cracking price. The 500g box is £1.95 so you're paying a whopping 73p less for for 250g more scrummy Shreddies. There were loads on the shelves and when I've just visited their website they're on offer there as well.
Hope that this is of use to somebody, my cupboards are full of the damn things now!!