Here's a one dollar auction with no reserve for a LOT of firebrick, which must be picked up in Kansas City. No connection with seller, but you might get a truckload for the cost of a few bricks.
http://cgi.ebay.com/Firebrick-Fire-B...mZ130035242395
http://cgi.ebay.com/Firebrick-Fire-B...mZ130035242395