Lime company purchased $300$ units for $$40$ each on January $31.$ It purchased $100$ units for $$20$

each on February $28.$ It sold a total of $170$ units for $$100$ each from March $1$ through December $31.$

If the company uses the last$-$in$,$ first$-$out inventory costing method, calculate the cost of ending

inventory on December $31.($Assume that the company uses a perpetual inventory system.$)$