An entrepreneur is going to produce a total of at least six sample fasteners combined. It costs $9 to produce each metal fastener and $4 for each plastic fastener. He wants to have at least two of each version of the fastener and needs all samples in 24 hours. It takes 4 hours to produce each metal sample and 2 hours to produce each plastic sample. To minimize the cost of the samples, how many of each kind should the entrepreneur order? What will be the cost of the samples?