Sunland Bookstore had 510 units on hand at January 1, costing $9 each. Purchases and sales during the month of January were as follows: Date Purchases Sales Jan. 14 370 @ $13 17 250 @ $12 25 250 @ $10 29 260 @ $17 Sunland does not maintain perpetual inventory records. According to a physical count, 380 units were on hand at January 31. The cost of the inventory at January 31, under the LIFO method is: $3800. $4060. $4560. $3420.