John and Jade make T$-$shirts. They sew together $500$ plain white $T-$shirts each month that can be sold for $$10$ per unit. Variable costs are $$3\mathrm{.}50$ per shirt. They could process these T$-$shirts further by printing logos on each shirt. This extra processing would cost $$2,000$ for equipment and an additional $$1\mathrm{.}50$ per shirt. However, the shirts could then be sold for $$18$ per unit. What is the increase $($or decrease$)$ in Net Income that would result from printing the logos on each shirt?