I made mine out of some old pine shelving. I did one side, but the piece of wood I have isn't wide enough for the other side, so while the glue is setting, I'm posting my results.
I'll coat it with some mineral oil or something when I'm done. It gives it a nice butcher block appearance. Since the shelf was just sitting in the scrap wood pile in my garage, the total cost of this project was just the time I put into it.