Looking to Purchase Limestone near Columbia, MD

[Zain B.]

Hello BP nation, 

I am looking to purchase 6 pieces of Limestone sized 87 inches by 12 inches near columbia Maryland. My handyman / contractor said that he is not looking for real stone but Limestone. Its supposed to cost around $50 (plus or minus). I called Home Depot and Lowe's and they both do not carry Limestone. The purpose of the Limestone is to install it on the exterior steps of a property that I am renovating. Any help that you can provide will be greatly appreciated. 

Thanks