Marriages Layer Pellets (GM free) £7.60 for 20kg bag)
Mixed corn - um, about the same.
If you order a pallet load (tonne), it's delivered free. They'll do a mixed pallet, so I get sheep pellets and pig food from them as well.
With the cost of diesel plus the cost of my time, I reckon it's worth it. Plus I'm not tempted to buy "stuff" in a shop.