Danford Company, a manufacturer of farm equipment, currently produces $20,000$ units of gas filters per

year for use in its lawn$-$mower production. The costs, based on the previous year's production, are

reported below. It is anticipated that gas$-$filter production will last five years. If the company continues to

produce the product in$-$house, annual direct material costs will increase $$\frac{3000}{?}$ year $($For example,

annual material costs during the first production year will be $$63,000.)$ Direct labor will also increase by

$$\frac{5000}{?}$ year. However, variable overhead costs will increase at the rate of $$\frac{2000}{?}$ year and the fixed

overhead will remain at its current level over the next five years. John Holland Company has offered to

sell Danford $20,000$ units of gas filters for $$25$ per unit. If Danford accepts the offer, some of the

manufacturing facilities currently used to manufacture the filter could be rented to a third party for

$$35,000$ per year. The firm's interest rate is known to be $15\%.$ What is the unit cost of buying the gas

filter from the outside source? Determine whether Danford should off load or manufacture?$($Use net annual worth method$)$