Hannon Retailing Company prices its products by adding $30\%$ to its cost. Hannon anticipates sales of $$715,000$ in July, $$728,000$ in August, and $$624,000$ in September. Hannon's policy is to have on hand enough inventory at the end of the month to cover $25\%$ of the next month's sales. What will be the cost of the inventory that Hannon should budget for purchase in August?

a$.$ $$560,000$

b$.$ $$540,000$

c$.$ $$680,000$

d$.$ $$509,600$