A salesman has scheduled two appointments to sell encyclopedias. His first appointment will lead to a sale with probability $.3,$ and his second will lead independently to a sale with probability .6. Any sale made is equally likely to be either for the deluxe model, which costs $\$ 1000$, or the standard model, which costs $\$ 500 .$ Determine the probability mass function of $X,$ the total dollar value of all sales.