Jenny sells beauty supplies. Her annual demand for a particular skin lotion is 2,000 units. The cost of placing an order is $200, while the holding cost per unit per year is 20% of the cost. This item currently costs $50 if the order quantity is less than 100. For orders between 100-399 units, the unit cost falls to $49. For orders of 400 units or more, the unit cost falls to $48.
To minimize total inventory cost:
(1) How many units should Jenny order each time she placed an order?
(2) What is the minimum annual total cost?