Production estimates for August are as follows: Estimated inventory (units), August 1 12,000 Desired inventory (units), August 31 9,000 Expected sales volume (units), August 75,000 For each unit produced, the direct materials requirements are as follows: Material A ($5 per lb.) 3 lbs. Material B ($18 per lb.) 1/2 lb. The total direct materials purchases (assuming no beginning or ending inventory of material) of Materials A and B required for August production is