During the month of June, Ace Incorporated purchased goods from two suppliers. The sequence of events was as follows:

June $3$ Purchased goods for $$4,500$ from Diamond Incorporated with terms $2/12,$ n$/45.$

June $5$ Returned goods costing $$1,300$ to Diamond Incorporated for credit on account.

June $6$ Purchased goods from Club Corporation for $$1,200$ with terms $2/12,$ n$/45.$

June $11$ Paid the balance owed to Diamond Incorporated.

June $22$ Paid Club Corporation in full.

Required:

Assume that Ace uses a perpetual inventory system and that the company had no inventory on hand at the beginning of the month. Calculate the cost of inventory as of June $30.$ What is the cost of inventory?