The clay for the oven came from a local gravel quarry. They hate hitting clay veins and happily give it away. I got it from a woman who bought an entire semi load of this clay for only the cost of the driver's time. She used the clay to make an entire cob house (see picture below).
I tried to use some old fire bricks that I got off Craig's List. It quickly became obvious that used bricks are just too imperfect and would simply not work for the oven floor. So we had to purchase new bricks but ended up using all the old fire bricks to build the attached grill area.
The only other building component that had to be purchased was the sand. I'm sure that if we had of just tried, we probably could have gotten the sand for cheap or free but instead we just got it from the masonry section at The Home Depot.
