The wood is pretty unique. It looks like wood and I like how the mouth is the crack between the pieces of wood.
The ore looks more like a smiling lump of coal or a grey raincloud. Pass.
The bricks look very orange in the picture, not red. They also look shy for some reason.
The wheat reminds me of a bunch of yellow broccoli for some reason. I expect it to start singing and dancing to inform me about the dangers of poor nutrition. What are those white things on the side? Hands? Ears? Wings?
The prices on these things range from $4.00 to $8.00 each online... Check out http://www.scifigenre.com/itemDetail.aspx?nItemID=96719 for the lowest price I've seen if you've GOT to have them.
Myself, I would say if you wanted to play with these alternate rules, use a brick, a rock from your back yard, a stick, a ball of wool, and some straw or hay in a baggie. Or, just write the words WOOD, BRICK, WHEAT, SHEEP, and ORE on index cards. There. I just saved you $40.