I keep on seeing them at B & M Bargains, they are a hellova lot cheaper than those on the link. But I have collected and inherited so many tins in just about every shape and size I don't need any more.
I have got a silicone sheet, had it for years for doing pasties and cookies on and I think that it is wonderful it just rinses out and rolls up for storage. Never sticks even when gravy runs out.