All of these 3 have been road tested in Yeovil, and extensively 'borrowed' for elsewhere, and they all work really well:
Chocolate Christmas - telling the story through chocolates and sweets. Or just browse the chocolate aisle of your local supermarket and see what names jump off the shelf.
Merry Crispmas - telling the story through brands and flavours of crips and snacks
Fruit and Veg Christmas - well, you get the idea
and just in case these inspire you, here's a chocolate version of the Easter story.
To avoid spending lots of cash, you could use pictures rather than the real thing. But it's quite fun rummaging through for the next item whilst everyone tries to guess what it is. Enjoy.