Order between $1$ and $29$ units for a price per unit of $$9\mathrm{.}00$

Order between $30$ and $99$ units for a price per unit of $$8\mathrm{.}80$

Order $100$ units or more for a price per unit of $$8\mathrm{.}50$

Annual demand $=1200$ units

Ordering costs $=$ $$10$ per order

Carrying costs $=$ $$2\mathrm{.}50$ per unit per year