Harold sells bags of soil to its customers for $$7$ per bag. It costs Harold $$1$ in direct labour to retrieve and bag the soil. The pre$-$printed bag costs Harold $$1$ from a local plastics supplier. It also costs Harold $$1\mathrm{.}50$ per bag in delivery fees. Other costs include management salaries of $$2,500$ per month, advertising of $$500$ per month. How many bags of soil does Harold need to sell per month to break even?