Ok, so I used the foam core, but hate cutting it as it seems to shred and leave uneven edges. Even covering with fondant or ribbon does not work sometimes. And it still bows on a heavy cake.
Masonite seems more sturdy but costly to add to a cake Im trying to keep in a cost effective price range. I know I can "rent" them out but sometimes the cakes are an hour away.
So what do you use as your cake board, thats sturdy and semi cost effective? Any other great ideas out there?

Hi, I always use thick cake drums. Here is the link from country kitchen sweetart.

http://www.countrykitchensa.com/catalog/product.aspx?T=1&ShopId=38&CatId=537&SubCatId=91&productId=626808