I have some odd pieces of Aragocrete, big and small, that could sub for base rock. I put about $45 for materials into this project, kept some, and at the last FW club auction, bought some 5 gallon plastic buckets, filled them up with the nice pieces, and they all sold for less than I paid for the buckets. I will probably make out if I give them to you. One guy bought all four buckets for $1 each and was really happy, but no one else had a clue what the stuff was.